JUDGMENT

Present: President DONOGHUE; Vice-President GEVORGIAN; Judges TOMKA, ABRAHAM, BENNOUNA, YUSUF, XUE, SEBUTINDE, BHANDARI, ROBINSON, SALAM, IWASAWA, NOLTE, CHARLESWORTH, BRANT; Judges ad hoc MCRAE, SKOTNIKOV;

Registrar Gautier.

In the case concerning the question of the delimitation of the continental shelf between Nicaragua and Colombia beyond 200 nautical miles from the Nicaraguan coast,

between

the Republic of Nicaragua,

represented by

HE Mr Carlos José Argüello Gómez, Permanent Representative of the Republic of Nicaragua to the international organizations based in the Kingdom of the Netherlands, member of the International Law Commission,

as Agent and Counsel;

Mr Alex Oude Elferink, Director, Netherlands Institute for the Law of the Sea, Professor of International Law of the Sea at Utrecht University,

Mr Vaughan Lowe, KC, Emeritus Chichele Professor of Public International Law, University of Oxford, member of the Institut de droit international, member of the Bar of England and Wales,

Mr Alain Pellet, Emeritus Professor of the University Paris Nanterre, former Chairman of the International Law Commission, President of the Institut de droit international,

as Counsel and Advocates;

Ms Claudia Loza Obregon, Legal Adviser, Ministry of Foreign Affairs of the Republic of Nicaragua,

Mr Benjamin Samson, Centre de droit international de Nanterre (CEDIN), University Paris Nanterre,

as Assistant Counsel;

Mr Robin Cleverly, MA, DPhil, CGeol, FGS, Law of the Sea Consultant, Marbdy Consulting Ltd,

as Scientific and Technical Adviser;

Ms Sherly Noguera de Argüello, Consul General of the Republic of Nicaragua,

as Administrator,

and

the Republic of Colombia,

represented by

HE Mr Eduardo Valencia-Ospina, former Registrar and Deputy-Registrar of the International Court of Justice, former member, Special Rapporteur and Chairman of the International Law Commission,

as Agent and Counsel;

HE Ms Carolina Olarte-Bácares, Dean of the School of Law at the Pontificia Universidad Javeriana, member of the Permanent Court of Arbitration, Ambassador of the Republic of Colombia to the Kingdom of the Netherlands,

HE Ms Elizabeth Taylor Jay, former Ambassador of the Republic of Colombia to the Republic of Kenya, former Permanent Representative of the Republic of Colombia to the United Nations Environment Programme and the United Nations Human Settlements Programme,

as Co-Agents;

HE Mr Álvaro Leyva Durán, Minister for Foreign Affairs of the Republic of Colombia,

HE Mr Everth Hawkins Sjogreen, Governor of San Andrés, Providencia and Santa Catalina, Republic of Colombia,

as National Authorities;

Mr W. Michael Reisman, Myres S. McDougal Professor Emeritus of International Law, Yale University, member of the Institut de droit international,

Sir Michael Wood, KCMG, KC, former member of the International Law Commission, member of the Bar of England and Wales,

Mr Rodman R. Bundy, former avocat à la Cour d'appel de Paris, member of the Bar of the State of New York, partner at Squire Patton Boggs LLP, Singapore,

Mr Jean-Marc Thouvenin, Professor at the University Paris Nanterre, Secretary-General of the Hague Academy of International Law, associate member of the Institut de droit international, member of the Paris Bar, Sygna Partners,

Ms Laurence Boisson de Chazournes, Professor of International Law and International Organization at the University of Geneva, Professor at the Collège de France (2022-2023), member of the Institut de droit international,

Mr Lorenzo Palestini, Lecturer at the Graduate Institute of International and Development Studies and at the University of Geneva,

as Counsel and Advocates;

Mr Andrés Villegas Jaramillo, Co-ordinator, Group of Affairs before the International Court of Justice at the Ministry of Foreign Affairs of the Republic of Colombia, associate of the Instituto Hispano-Luso-Americano de Derecho Internacional,

Mr Makane Moïse Mbengue, Professor at the University of Geneva, Director of the Department of Public International Law and International Organization, associate member of the Institut de droit international,

Mr Eran Sthoeger, Esq., Adjunct Professor of International Law at Brooklyn Law School and Seton Hall Law School, member of the Bar of the State of New York,

Mr Alvin Yap, Advocate and Solicitor of the Supreme Court of Singapore, Squire Patton Boggs LLP, Singapore,

Mr Gershon Hasin, Visiting Lecturer in Law at Yale University,

Mr Gabriel Cifuentes, adviser to the Minister for Foreign Affairs of the Republic of Colombia, as Counsel;

Ms Jenny Bowie Wilches, First Secretary, Embassy of the Republic of Colombia in the Kingdom of the Netherlands,

Ms Viviana Andrea Medina Cruz, Second Secretary, Embassy of the Republic of Colombia in the Kingdom of the Netherlands,

Mr Raúl Alfonso Simancas Gómez, Third Secretary, Embassy of the Republic of Colombia in the Kingdom of the Netherlands,

Mr Oscar Casallas Méndez, Third Secretary, Group of Affairs before the International Court of Justice,

Mr Carlos Colmenares Castro, Third Secretary, Group of Affairs before the International Court of Justice, as representatives of the Ministry of Foreign Affairs of the Republic of Colombia;

Rear Admiral Ernesto Segovia Forero, Chief of Naval Operations,

CN Hermann León, Delegate of Colombia to the International Maritime Organization,

CN William Pedroza, National Navy of Colombia, Director of Maritime and Fluvial Interests Office,

as representatives of the Navy of the Republic of Colombia;

Mr Lindsay Parson, Geologist, Director of Maritime Zone Solutions Ltd, United Kingdom, former member and Chair of the United Nations International Seabed Authority's Legal and Technical Commission,

Mr Peter Croker, Geophysicist, Consultant at The M Horizon (UK) Ltd, former Chair of the United Nations Commission on the Limits of the Continental Shelf,

Mr Walter R. Roest, Geophysicist, Director of Roest Consultant EIRL, France, member of the United Nations Commission on the Limits of the Continental Shelf,

Mr Scott Edmonds, Cartographer, Director of International Mapping, Mr Thomas Frogh, Cartographer, International Mapping,

as Technical Advisers,

The Court,

composed as above,

after deliberation,

delivers the following Judgment:

1. On 16 September 2013, the Government of the Republic of Nicaragua (hereinafter “Nicaragua”) filed in the Registry of the Court an Application instituting proceedings against the Republic of Colombia (hereinafter “Colombia”) with regard to a dispute concerning “the delimitation of the boundaries between, on the one hand, the continental shelf of Nicaragua beyond the 200-nautical-mile limit from the baselines from which the breadth of the territorial sea of Nicaragua is measured, and on the other hand, the continental shelf of Colombia”.

2. In its Application, Nicaragua sought to found the jurisdiction of the Court on Article XXXI of the American Treaty on Pacific Settlement signed on 30 April 1948, officially designated, according to Article LX thereof, as the “Pact of Bogotá”.

3. In accordance with Article 40, paragraph 2, of the Statute of the Court, the Registrar immediately communicated the Application to the Government of Colombia. He also notified the Secretary-General of the United Nations of the filing of the Application by Nicaragua.

4. Pursuant to Article 40, paragraph 3, of the Statute of the Court, the Registrar notified the Members of the United Nations through the Secretary-General of the filing of the Application, by transmission of the printed bilingual text.

5. Since the Court included upon the Bench no judge of the nationality of either Party, each Party proceeded to exercise the right conferred upon it by Article 31, paragraph 3, of the Statute to choose a judge ad hoc to sit in the case. Nicaragua chose Mr Leonid Skotnikov. Colombia first chose Mr Charles N. Brower, who resigned on 5 June 2022, and subsequently Mr Donald McRae.

6. By an Order of 9 December 2013, the Court fixed 9 December 2014 and 9 December 2015 as the respective time-limits for the filing of a Memorial by Nicaragua and a Counter-Memorial by Colombia.

7. On 14 August 2014, before the expiry of the time-limit for the filing of the Memorial of Nicaragua, Colombia, referring to Article 79 of the Rules of Court of 14 April 1978 as amended on 1 February 2001, raised preliminary objections to the jurisdiction of the Court and to the admissibility of the Application. By an Order of 19 September 2014, the Court, noting that by virtue of Article 79, paragraph 5, of the Rules of Court the proceedings on the merits were suspended, fixed 19 January 2015 as the time-limit for the presentation by Nicaragua of a written statement of its observations and submissions on the preliminary objections raised by Colombia. Nicaragua filed its statement within the time-limit thus fixed.

8. By a letter dated 10 November 2014, pursuant to the instructions of the Court under Article 43, paragraph 1, of the Rules of Court, the Registrar addressed to States parties to the Pact of Bogotá the notification provided for in Article 63, paragraph 1, of the Statute of the Court. In accordance with the provisions of Article 69, paragraph 3, of the Rules of Court, the Registrar also addressed to the Organization of American States (hereinafter the “OAS”) the notification provided for in Article 34, paragraph 3, of the Statute. By letter dated 5 January 2015, the Secretary-General of the OAS indicated that the Organization did not intend to present any observations in writing within the meaning of Article 69, paragraph 3, of the Rules of Court.

9. By a letter dated 17 February 2015, the Government of the Republic of Chile (hereinafter “Chile”), referring to Article 53, paragraph 1, of the Rules of Court, asked to be furnished with copies of the pleadings and documents annexed in the case. Having ascertained the views of the Parties in accordance with that same provision, the President of the Court decided to grant that request. The Registrar duly communicated that decision to the Government of Chile and to the Parties. Copies of the preliminary objections raised by Colombia and the written statement of its observations and submissions thereon filed by Nicaragua were therefore communicated to Chile.

10. Public hearings on the preliminary objections raised by Colombia were held on 5, 6, 7 and 9 October 2015. In its Judgment of 17 March 2016, the Court found that it had jurisdiction, on the basis of Article XXXI of the Pact of Bogotá, to entertain the first request put forward by Nicaragua in its Application (see paragraph 18 below), asking the Court to determine “[t]he precise course of the maritime boundary between Nicaragua and Colombia in the areas of the continental shelf which appertain to each of them beyond the boundaries determined by the Court in its Judgment of 19 November 2012” in the case concerning Territorial and Maritime Dispute (Nicaragua v. Colombia), and that this request was admissible (Question of the Delimitation of the Continental Shelf between Nicaragua and Colombia beyond 200 Nautical Miles from the Nicaraguan Coast (Nicaragua v. Colombia), Preliminary Objections, Judgment, I.C.J. Reports 2016 (I), p. 140, para. 126).

11. By an Order of 28 April 2016, the Court fixed 28 September 2016 and 28 September 2017, respectively, as the new time-limits for the filing of a Memorial by Nicaragua and a Counter-Memorial by Colombia. These pleadings were filed within the time-limits thus fixed. Along with its Memorial, Nicaragua also provided to the Court copies of its full submission to the Commission on the Limits of the Continental Shelf (hereinafter the “CLCS” or the “Commission”), explaining that this submission was part of its Memorial and that it was classified as confidential in accordance with the rules contained in Annex II to the Rules of Procedure of the CLCS.

12. By letters dated 6 October 2016 and 22 November 2016, respectively, the Government of the Republic of Costa Rica (hereinafter “Costa Rica”) and the Government of the Republic of Panama (hereinafter “Panama”), referring to Article 53, paragraph 1, of the Rules of Court, asked to be furnished with copies of the pleadings and documents annexed in the case. Having ascertained the views of the Parties in accordance with the same provision, the Court granted those requests, with the exception of the submission of Nicaragua to the CLCS, which would not be provided to Costa Rica and Panama. The Registrar duly communicated those decisions to Costa Rica and Panama and to the Parties. A copy of Nicaragua's Memorial, not including said submission, was also made available to Chile (see paragraph 9 above).

13. By an Order of 8 December 2017, the Court authorized the submission of a Reply by Nicaragua and a Rejoinder by Colombia, and fixed 9 July 2018 and 11 February 2019 as the respective time-limits for the filing of those pleadings. The Reply of Nicaragua and the Rejoinder of Colombia were filed within the time-limits thus fixed.

14. In an Order of 4 October 2022, the Court indicated that, in the circumstances of the case, before proceeding to any consideration of technical and scientific questions in relation to the delimitation of the continental shelf between Nicaragua and Colombia beyond 200 nautical miles from the baselines from which the breadth of the territorial sea of Nicaragua is measured, it was necessary to decide on certain questions of law, after hearing the Parties thereon. Accordingly, the Court decided that,

15. Having ascertained the views of the Parties and in light of the scope of the oral proceedings, the Court decided, pursuant to Article 53, paragraph 2, of the Rules of Court, that copies of the written pleadings and documents annexed would not be made accessible to the public at the time of the opening of the oral proceedings.

16. Public hearings on the two questions formulated by the Court in its Order of 4 October 2022 (see paragraph 14 above) were held on 5, 6, 7 and 9 December 2022, at which the Court heard the oral arguments and replies of:

For Nicaragua: HE Mr Carlos José Argüello Gómez,

Mr Vaughan Lowe,

Mr Alex Oude Elferink,

Mr Alain Pellet.

For Colombia: HE Mr Eduardo Valencia-Ospina,

Sir Michael Wood,

Mr Rodman Bundy,

Mr Lorenzo Palestini,

Mr Jean-Marc Thouvenin,

Ms Laurence Boisson de Chazournes.

17. At the hearings, a Member of the Court put a question to Colombia, to which a reply was given orally in accordance with Article 61, paragraph 4, of the Rules of Court. Nicaragua submitted written comments on the oral reply provided by Colombia on 15 December 2022.

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18. In the Application, the following claims were made by Nicaragua: “Nicaragua requests the Court to adjudge and declare:

1. 1. First: The precise course of the maritime boundary between Nicaragua and Colombia in the areas of the continental shelf which appertain to each of them beyond the boundaries determined by the Court in its Judgment of 19 November 2012.

2. 2. Second: The principles and rules of international law that determine the rights and duties of the two States in relation to the area of overlapping continental shelf claims and the use of its resources, pending the delimitation of the maritime boundary between them beyond 200 nautical miles from Nicaragua's coast.”

19. In the written proceedings, the following submissions were presented by the Parties:

On behalf of the Government of Nicaragua,

in the Memorial:

in the Reply:

On behalf of the Government of Colombia,

in the Counter-Memorial:

in the Rejoinder:

20. At the oral proceedings, the following submissions were presented by the Parties:

On behalf of the Government of Nicaragua,

On behalf of the Government of Colombia,

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*  *

I. GENERAL BACKGROUND

21. The maritime areas with which the present proceedings are concerned are located in the Caribbean Sea, an arm of the Atlantic Ocean partially enclosed to the north and east by a number of islands, and bounded to the south and west by South and Central America. Nicaragua's eastern coast faces the south-western part of the Caribbean Sea. To the north of Nicaragua lies Honduras and to the south lie Costa Rica and Panama. To the north-east, Nicaragua faces Jamaica, and to the east, it faces the mainland coast of Colombia. Colombia is situated to the south of the Caribbean Sea. On its Caribbean front, Colombia is bordered to the west by Panama and to the east by Venezuela. The Colombian islands of San Andrés, Providencia and Santa Catalina lie in the south-west of the Caribbean Sea, approximately 100 to 150 nautical miles to the east of the Nicaraguan coast. (For the general geography of the area, see sketch-map No. 1.)

Sketch-map No. 1:

General Geography

22. On 6 December 2001, Nicaragua filed in the Registry of the Court an Application instituting proceedings against Colombia in respect of a dispute consisting of “a group of related legal issues subsisting” between the two States “concerning title to territory and maritime delimitation” in the western Caribbean (case concerning Territorial and Maritime Dispute (Nicaragua v. Colombia)).

23. In the Judgment rendered by the Court on 19 November 2012 in.the case concerning Territorial and Maritime Dispute (Nicaragua v. Colombia) (hereinafter the “2012 Judgment”), the Court decided that Colombia “has sovereignty over the islands at Alburquerque, Bajo Nuevo, East-Southeast Cays, Quitasueño, Roncador, Serrana and Serranilla” (I.C.J. Reports 2012 (II), p. 718, para. 251, subpara. 1). The Court also established a single maritime boundary delimiting the continental shelf and the exclusive economic zones of Nicaragua and Colombia up to the 200-nautical-mile limit from the baselines from which the territorial sea of Nicaragua is measured (ibid., pp. 719-720, para. 251, subpara. 4). The Court, however, noted in its reasoning that, since Nicaragua had not yet notified the Secretary-General of the United Nations of the location of those baselines under Article 16, paragraph 2, of the 1982 United Nations Convention on the Law of the Sea (hereinafter “UNCLOS” or the “Convention”), the precise location of the eastern endpoints of the maritime boundary could not be determined and was therefore depicted only approximately on the sketch-map included at page 714 of that Judgment (ibid., p. 713, para. 237). (For the course of the maritime boundary established by the Court in its 2012 Judgment, see sketch-map No. 2.)

Sketch-map No. 2:

Course of the maritime boundary established by the Court in its 2012 Judgment 28.

24. In the 2012 Judgment, the Court further found that it could not uphold Nicaragua's claim contained in its final submission I (3), requesting that the Court adjudge and declare that

In particular, the Court noted that,

The Court observed in this regard that Nicaragua had submitted to the CLCS only “Preliminary Information” which “[fell] short of meeting the requirements for information on the limits of the continental shelf beyond 200 nautical miles” to be submitted under Article 76, paragraph 8, of UNCLOS (ibid., p. 669, para. 127).

25. On 24 June 2013, in accordance with Article 76, paragraph 8, of UNCLOS, Nicaragua presented its full submission to the CLCS regarding the limits of its continental shelf beyond 200 nautical miles from the baselines from which the breadth of its territorial sea is measured.

26. On 16 September 2013, Nicaragua filed the Application instituting the current proceedings, requesting the Court to adjudge and declare the precise course of the maritime boundary between Nicaragua and Colombia in the areas of the continental shelf which appertain to each of them beyond the boundaries determined by the Court in its 2012 Judgment (see paragraph 1 above).

Both Parties have adduced extensive technical and scientific evidence as to whether Nicaragua has established an entitlement to a continental shelf beyond 200 nautical miles from the baselines from which the breadth of the territorial sea is measured (also referred to as an “extended continental shelf”) and, if so, the precise outer limits of that continental shelf.

II. OVERVIEW OF THE PARTIES' POSITIONS

27. Nicaragua argues that it has an entitlement to a continental shelf beyond 200 nautical miles of its coast. In order to substantiate its claim, Nicaragua relies on the submission that it presented to the CLCS on 24 June 2013, which, in its view, contains “complete technical information” that enables the Commission to review that submission and make its recommendations under Article 76, paragraph 8, of UNCLOS on the outer limits of Nicaragua's continental shelf. Nicaragua contends that it has established the existence of a natural prolongation of its land territory up to the outer edge of the continental margin and that there is both geological and geomorphological continuity between its landmass and the sea-bed and subsoil beyond 200 nautical miles from its baselines.

28. Nicaragua defines the outer edge of the continental margin, wherever the margin extends beyond 200 nautical miles of its coast, by reference to the formulae and criteria contained in Article 76, paragraphs 4 to 6, of UNCLOS. It asserts that the CLCS applies these provisions to determine the existence of a State's entitlement to a continental shelf beyond 200 nautical miles. According to Nicaragua, Article 76, paragraphs 2 to 6, of UNCLOS reflect customary international law.

29. Nicaragua notes that Colombia only claims, with respect to its mainland, a continental shelf up to 200 nautical miles from its baselines. Nicaragua proposes, with respect to Colombia's mainland, a provisional delimitation line which Nicaragua refers to as the “provisional mainland-mainland delimitation line”. This line divides equally the area of overlap between the 200-nautical-mile limit of the continental shelf entitlement generated by Colombia's mainland coast and the outer limits of the extended continental shelf as described by Nicaragua in its submission to the CLCS. That line is depicted in figure 5.1 of Nicaragua's Memorial, which is reproduced below.

30. With respect to the entitlement derived from Colombian islands, Nicaragua contends that only the maritime features of San Andrés, Providencia and Santa Catalina qualify as islands entitled to a continental shelf in accordance with the customary rule reflected in Article 121, paragraph 2, of UNCLOS, whereas Quitasueño, Alburquerque, Bajo Nuevo, East-Southeast Cays, Roncador, Serrana and Serranilla fall under the definition of “rocks” under customary international law reflected in Article 121, paragraph 3, of UNCLOS and do not generate any entitlement to a continental shelf. Nicaragua considers that San Andrés, Providencia and Santa Catalina are situated on the same continental margin as Nicaragua's mainland and hence could have a potential continental shelf entitlement beyond 200 nautical miles to the edge of that continental margin. In Nicaragua's view, however, the continental shelf of these islands should not extend east of the 200-nautical-mile limit from Nicaragua's baselines because the 2012 Judgment already allocated these islands continental shelf rights that are very substantial in relation to their limited size. Thus, Nicaragua is of the view that these islands are entitled to a continental shelf up to a line consisting of 200-nautical-mile arcs from the baselines from which the territorial sea of Nicaragua is measured connecting points A, C and B, the co-ordinates of which are indicated in the submissions presented by Nicaragua in its Memorial and reiterated in its Reply (see paragraph 19 above). Nicaragua also considers that the Colombian maritime features of Serranilla Cay and Bajo Nuevo should be afforded only a 12-nautical-mile territorial sea. The final delimitation proposed by Nicaragua is depicted in figure 7.1. of its Reply, which is reproduced below.

Map showing the “provisional mainland-mainland delimitation line” proposed by Nicaragua

(Source: Nicaragua's Memorial, figure 5.1, p. 128)

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31. Colombia asks the Court to reject Nicaragua's request for a delimitation of the continental shelf beyond 200 nautical miles of the latter's coast. It argues in particular that, as a matter of customary international law, a State may not claim a continental shelf beyond 200 nautical miles from its baselines that encroaches on another State's entitlement to a 200-nautical-mile exclusive economic zone and continental shelf measured from its mainland coast and islands.

32. With respect to the alleged entitlement of Nicaragua to a continental shelf beyond 200 nautical miles of Nicaragua's coast, Colombia argues that the Applicant erroneously assumes that its submission to the CLCS is in itself proof of the existence of its extended continental shelf. According to Colombia, Article 76, paragraphs 2 to 6, which set out precise scientific and technical formulae for fixing limits beyond which an extended continental shelf may not be claimed, do not reflect customary international law. The Respondent contends that a coastal State's entitlement to a continental shelf beyond 200 nautical miles must be based on the natural prolongation of its land territory as evidenced by the physical characteristics of the shelf based on geological and geomorphological factors. In this regard, Colombia argues that Nicaragua fails to demonstrate with scientific certainty the existence of the natural prolongation of its land territory beyond 200 nautical miles of its coast. Colombia claims that there are a number of fundamental geomorphological disruptions and geological discontinuities in the physical continental shelf that terminate the natural prolongation of Nicaragua's land territory well before the 200-nautical-mile limit from the Nicaraguan coast is reached.

Map showing the final delimitation proposed by Nicaragua

(Source: Nicaragua's Reply, figure 7.1, p. 208)

33. Turning to its own entitlements, Colombia alleges that, in conformity with customary international law, both its mainland and its islands are entitled to a 200-nautical-mile exclusive economic zone with its “attendant” continental shelf. It recalls that, in the 2012 Judgment, the Court ruled that San Andrés, Providencia and Santa Catalina generated a territorial sea, an exclusive economic zone and a continental shelf, and that they possessed substantial entitlements to the east of the 200-nautical-mile line from Nicaragua's baselines. Colombia further asserts that Roncador, Serrana, Serranilla and Bajo Nuevo are not rocks and are thus entitled to an exclusive economic zone with its “attendant” continental shelf, including in areas lying more than 200 nautical miles from Nicaragua's baselines. It contends that all these islands are capable of sustaining human habitation or economic life of their own. It adds that, even if Serrana, Roncador, Serranilla and Bajo Nuevo were deemed not to be entitled to an exclusive economic zone and continental shelf, Nicaragua's claim would still fail because its extended continental shelf cannot “leapfrog” over or “tunnel” under the exclusive economic zone and “attendant” continental shelf of San Andrés, Providencia and Santa Catalina.

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34. In its Order of 4 October 2022, the Court stated that, in the circumstances of the case, it was first necessary to decide on certain questions of law, after hearing the Parties thereon, and thus posed two questions to the Parties (see paragraph 14 above). The Court will examine the first question (Part III) before turning to the second question (Part IV). It will then consider the requests contained in Nicaragua's submissions (Part V).

III. FIRST QUESTION FORMULATED IN THE ORDER OF 4 OCTOBER 2022

35. The Court recalls that the first question formulated in the Order of 4 October 2022 (hereinafter the “first question”) is worded as follows:

36. The Court will begin by considering the preliminary character of the first question (Section A). It will then determine the customary international law applicable in this case to the maritime areas at issue (Section B), before responding to the first question (Section C).

IV. SECOND QUESTION FORMULATED IN THE ORDER OF 4 OCTOBER 2022

80. The Court recalls that the second question formulated in the Order of 4 October 2022 is worded as follows:

81. The Court concluded, in response to the first question, that a State's entitlement to a continental shelf beyond 200 nautical miles from the baselines from which the breadth of its territorial sea is measured may not extend within 200 nautical miles from the baselines of another State (see paragraph 79 above). Therefore, even if a State can demonstrate that it is entitled to an extended continental shelf, that entitlement may not extend within 200 nautical miles from the baselines of another State.

82. It follows from the Court's answer to the first question that, regardless of the criteria that determine the outer limit of the extended continental shelf to which a State is entitled, its extended continental shelf cannot overlap with the area of continental shelf within 200 nautical miles from the baselines of another State. In the absence of overlapping entitlements over the same maritime areas, the Court cannot proceed to a maritime delimitation (see paragraph 42 above). Consequently, there is no need for the Court to address the second question.

V. CONSIDERATION OF NICARAGUA'S SUBMISSIONS

83. Based on the conclusion reached above (see paragraph 79), the Court now turns to the requests contained in Nicaragua's submissions.

84. In this regard, the Court recalls that Nicaragua's Application asks the Court to determine “[t]he precise course of the maritime boundary between Nicaragua and Colombia in the areas of the continental shelf which appertain to each of them beyond the boundaries determined by the Court in [the 2012 Judgment]”. Throughout the proceedings in the present case, Nicaragua has maintained that the object of its request consists in the delimitation of that maritime boundary. During the oral proceedings, Nicaragua explained that the submissions in its Memorial and Reply merely add precision to the request made in its Application. The Court considers that Nicaragua's submissions must be examined against this background.

I. SCOPE AND MEANING OF THE FIRST QUESTION

10. The Court's first question concerns only one step in the delimitation process. As the Judgment correctly points out, “[a]n essential step in any delimitation is to determine whether there are entitlements, and whether they overlap” (Judgment, para. 42). This step is essential for at least two reasons. For one, what States claim to be entitled to, and what they are in point of fact entitled to, do not always coincide; the Court must therefore determine for itself what the parties' entitlements are. It does so by identifying the parties' coasts that generate entitlements to maritime areas. Entitlements are said to “overlap” when the projections from the coast of one party overlap with projections from the coast of the other partyFootnote ¹⁰. This step is also essential because overlapping entitlements are a condition precedent for the Court to proceed to delimitation; in the absence of overlapping entitlements, there is simply nothing for the Court to delimit.

11. The Court's question is directed at this preliminary step of the delimitation process (which I will for convenience refer to simply as “the identification step”). The question has been framed in terms of law, as a legal question in general, not in terms of the circumstances of the present case.

12. At risk of stating the obvious, just because a State is entitled to a certain maritime area, this does not mean that it must obtain the full extent of that entitlement at the end of the delimitation process. Unlike a valid title over a certain territory, which implies the exclusion of any other title over the same territory, maritime entitlements have the particular feature that they can overlap with other maritime entitlementsFootnote ¹¹. As the Court explained in the Maritime Delimitation in the Black Sea case, the task of delimitation consists of “resolving the overlapping claims by drawing a line of separation of the maritime areas concerned”Footnote ¹². This requires that, so far as possible, the line of delimitation should “allow the coasts of the [p]arties to produce their effects in terms of maritime entitlements in a reasonable and mutually balanced way”Footnote ¹³. Entitlements can be amputated to achieve an equitable solution. The delimitation process often results in one or both parties not obtaining areas that they would otherwise be entitled to had it not been for the presence of the otherFootnote ¹⁴.

13. It follows that an affirmative answer to the Court's question in no way implies that Nicaragua must be allocated all, most — or indeed any — of the area where the Parties' entitlements might overlap within 200 nautical miles from Colombia's coast.

14. It is also useful to say a word about the problem which is at the heart of the Court's question and to put this problem into context. Usually, the identification step is a straightforward exercise, even when the parties disagree, for example, about the identification of their relevant coasts. Not so in the present case. The existence and breadth of Nicaragua's entitlement to a continental shelf beyond 200 nautical milesFootnote ¹⁵ must be determined by the application of the geomorphological and geological criteria set out in Article 76 of the Convention, rather than just the configuration of its coastsFootnote ¹⁶. To establish its entitlement, Nicaragua relies on its 2013 submission to the Commission. According to Nicaragua, this submission provides sufficient data to show that it has an entitlement to a continental shelf beyond 200 nautical miles in accordance with the geological and geomorphological criteria, the limits of which are subject to the constraints set out in Article 76, paragraph 5, of the Convention. Colombia opposes this claim. It argues that Nicaragua has not established that the natural prolongation from Nicaragua's land territory extends far enough to overlap with Colombia's 200-nautical-mile entitlement to the continental shelf, measured from Colombia's mainland coastFootnote ¹⁷.

If Colombia is correct on the facts, there would be no need for the Court to proceed to the delimitation as there would be no overlapping entitlements within 200 nautical miles from Colombia's mainland coast.

15. But this is not the problem at the heart of the Court's question. The problem at the heart of the Court's question — and of today's Judgment — is one of law. It concerns a situation where, in a given area, broad-margin State A claims an entitlement to a continental shelf beyond 200 nautical miles from its coast and within 200 nautical miles from the coast of State B, where the latter State has a continental shelf entitlement based on the 200 nautical miles distance criterion and an entitlement to an exclusive economic zone up to 200 nautical miles. This situation is not a new phenomenon, nor is it uncommon; international courts and tribunals have been faced with it on several occasions.

16. In the Delimitation of the Maritime Boundary in the Gulf of Maine Area case, the parties debated a similar issue, where Canada, for convenience, referred to an area of overlapping entitlements beyond 200 nautical miles from the United States' coast but within 200 nautical miles from its coast as the “grey area”Footnote ¹⁸. While the Chamber of the Court was not called upon to delimit the parties' entitlements in that area, the parties in that case advocated for different delimitation lines that created grey areas of varying sizes when extended seawardFootnote ¹⁹. This issue was also before the arbitral tribunal in the Arbitration between Barbados and the Republic of Trinidad and Tobago Footnote ²⁰. However, the tribunal took no position on “the substance of the problem”Footnote ²¹. Three other cases, namely the two cases concerning the delimitation in the Bay of Bengal, Delimitation of the Maritime Boundary in the Bay of Bengal (Bangladesh/Myanmar) Footnote ²² and Bay of Bengal Maritime Boundary Arbitration (Bangladesh v. India) Footnote ²³ (hereinafter the “Bay of Bengal cases”), as well as the Court's Judgment in the Maritime Delimitation in the Indian Ocean (Somalia v. Kenya) caseFootnote ²⁴, have also addressed this issue. I shall return to these cases and their implications below.

17. In the present case, the area of overlapping entitlements arises because Nicaragua claims a continental shelf entitlement beyond 200 nautical miles that extends far out into the Western Caribbean and within 200 nautical miles of Colombia's mainland coast, where it encounters Colombia's entitlement to a continental shelf based on the 200 nautical miles distance criterion.

18. At the identification step, such an area of overlap raises various questions of law which for some time had mostly been the concern of scholarly writingsFootnote ²⁵. One question is whether as a matter of law such an overlap of entitlements may occur in the first place. That is: is a State “prevented” from claiming its continental shelf entitlement beyond 200 nautical miles into an area that is claimed by another coastal State as its own continental shelf on the basis of the 200 nautical miles distance criterion? Colombia has strenuously argued that this is so.

19. It should be clear that today's Judgment is concerned with the area of overlapping entitlements at the identification step. The question is whether the Parties' entitlements overlap thus calling for a delimitation. How the Court should then approach delimiting the area of overlapping entitlements, and what the Parties' rights would be in such a maritime area, is a question of equitable delimitation that is not within the scope of the Court's first question. In this sense, it is important to distinguish between (1) an area of overlapping entitlements and (2) the maritime area that may be established by a court or tribunal. This distinction is important. The Respondent seems to assume that the existence of an area of overlapping entitlements in the Caribbean Sea within 200 nautical miles of its mainland coast necessarily means that the Court will have to establish the same kind of maritime area established, for instance, in the Bay of Bengal cases, with the same division of rights. This is not so. Should the Parties' entitlements overlap, it would be for the Court to adopt its own equitable solution.

20. I have set out these preliminary considerations in some length because they are necessary to understand the Court's first question.

II. ENTITLEMENT TO THE CONTINENTAL SHELF BEYOND 200 NAUTICAL MILES

21. The starting-point of the enquiry is Article 76, paragraph 1, of the Convention. While the Convention is not applicable as between the Parties, the Court has stated that the definition of the continental shelf set out therein forms part of customary international lawFootnote ²⁶. There is no doubt in my mind that the other key provisions defining the outer limits of the continental shelf beyond 200 nautical miles are also reflective of customary international lawFootnote ²⁷. The continental shelf concept cannot have a different meaning in customary international law than in the Convention. The Convention provides that the continental shelf of a coastal State comprises the seabed and subsoil of the submarine areas that either (a) extend “beyond its territorial sea throughout the natural prolongation of its land territory to the outer edge of the continental margin”, or (b) “to a distance of 200 nautical miles from the baselines from which the breadth of the territorial sea is measured where the outer edge of the continental margin does not extend up to that distance”Footnote ²⁸. In this respect, Article 76 of the Convention contains a series of complementary provisions that define the continental margin and specify how its outer edge is to be determined beyond 200 nautical miles.

22. The first key provision is paragraph 3, which defines the “continental margin”. The second key provision, contained in paragraph 4 (a) (i) and (ii), determines the position of the outer limit of the continental margin by means of the application of two rules (sometimes referred to as “formulae”). Both the “1 per cent sediment thickness formula” and the “60-nautical-mile distance formula” specified in paragraph (4) (a) are applied by reference to the foot of the continental slope, a geological feature. The result that one derives from the application of the formulae must then be subjected to the constraints specified in paragraph 5. The first constraint in paragraph 5 (the “distance constraint”) provides that the outer limits of the continental shelf may not exceed 350 nautical miles from the baselines from which the breadth of the territorial sea is measured. Alternatively, States may apply the second constraint in paragraph 5 (the “depth constraint”), which provides that the outer limits of the continental shelf may not exceed 100 nautical miles from the 2,500 metre isobath, which is a line connecting the depth of 2,500 metres.

23. The distance constraint of 350 nautical miles can be set aside when submarine elevations are still natural parts of the continental margin, such as its plateaux, rises, caps, banks and spursFootnote ²⁹.

24. A State can use the most favourable combination of the formulae in order to establish the outer edge of its continental margin and it can also use the most favourable combination of the depth and distance constraints to establish the outer limits of the continental shelfFootnote ³⁰.

25. If I have outlined the rules defining the outer limits of the continental shelf beyond 200 nautical miles in some detail, it is not to show that the determination of the outer limits of the continental shelf beyond 200 nautical miles is a complicated matter. It is to show what the rules bring and do not bring to the table; they bring in concepts of geodesy, geology, geophysics and hydrography, as well as very precise formulae and constraints. What they do not bring, however, is this: the notion that a State's entitlement to a continental shelf beyond 200 nautical miles “stops” at, or “cannot extend” within, 200 nautical miles from the baselines of another State.

26. The Convention is silent on the issue whether a State's entitlement to a continental shelf beyond 200 nautical miles may extend within 200 nautical miles from the baselines of another State. In the absence of a limitation to this effect, it must be accepted that the existence and breadth of a continental shelf entitlement beyond 200 nautical miles depend solely on the geological and geomorphological criteria set out above, subject to the applicable constraints under paragraph 5 of Article 76. This conclusion is in harmony with the cardinal principle, often repeated in delimitation cases, that “the land dominates the sea”. A State's maritime entitlements derive from its sovereignty over the land, notably its coast that generates maritime entitlements. As the Court observed in the North Sea Continental Shelf casesFootnote ³¹, and later in the Maritime Delimitation in the Black Sea caseFootnote ³², this principle is the basis for a continental shelf entitlement. The existence of a coastal State's continental shelf entitlement does not depend on the proximity to the coast of another State.

27. There is also no reservation in the Convention that specifies that a State's continental shelf entitlement beyond 200 nautical miles cannot overlap with the continental shelf within 200 nautical miles of another State. In the absence of such a reservation, it must be accepted that these entitlements may overlap. As mentioned above, a feature of maritime entitlements is that they can overlap with one another.

28. The Parties have referred extensively to the travaux préparatoires of the Convention in support of their arguments. But, as the Court's Judgment correctly notes, the issue of one State's continental shelf beyond 200 nautical miles extending within 200 nautical miles from the baselines of another State was “not debated during the Third United Nations Conference on the Law of the Sea” (Judgment, para. 76). This is not entirely surprising. It may be recalled that during the negotiation of the continental shelf régime, only 30 or so States were seen as possibly having continental margins beyond 200 nautical miles from their coasts that would call for the application of the delineation procedure set out in Article 76Footnote ³³. States may not have envisioned all aspects of this issue during the negotiations.

29. Despite the foregoing and the absence of any express limitation, in paragraph 76 of the Judgment, the Court seems inclined to find a tacit limitation to the entitlement to a continental shelf beyond 200 nautical miles on the basis of paragraphs 4 to 9 of Article 76, as well as Article 82, paragraph 1, of the Convention, which concerns payments and contributions with respect to the exploitation of the non-living resources of the continental shelf which would otherwise have been part of the Area.

The Judgment ventures that these provisions suggest that “the States participating in the negotiations assumed that the [continental shelf beyond 200 nautical miles] would only extend into maritime areas that would otherwise be located in the Area” — the implication being that a continental shelf beyond 200 nautical miles can only extend in the Area and not within 200 nautical miles from the baselines of another State (Judgment, para. 76, emphasis added). There is no trace of such an assumption in the travaux préparatoires of the Convention. In my view, this is a mere supposition which, even if accepted, could not jettison the clear text of the Convention.

The concept of the continental shelf had developed several decades before the adoption of the 1982 Convention. As the Court stated authoritatively in 1969, the rights of the coastal State in respect of the area of continental shelf that constitutes a natural prolongation of its land territory into and under the sea “exist ipso facto and ab initio, by virtue of its sovereignty over the land”Footnote ³⁴. States had long recognized this concept and accepted that it could extend beyond 200 nautical miles from a State's coast up to the continental slope, even if the precise outer limits of the continental shelf remained debatedFootnote ³⁵. For a time, the breadth of the continental shelf was conventionally defined with an exploitability testFootnote ³⁶. But this was rather imprecise. The formulae and constraints of Article 76 described above were the results of extensive negotiation, and they constituted an attempt at defining, but also limiting, the breadth of the continental shelves of broad-margin StatesFootnote ³⁷. They provide a methodology to establish the limits of the continental shelf. Given that the provisions of the Convention were subjected to scrutiny and extensive negotiation, the idea that the Convention imposes a tacit limitation on States' continental shelf entitlements beyond 200 nautical miles is untenable.

30. Thus, in my view, the answer to the question “may a State's entitlement to a continental shelf beyond 200 nautical miles . . . extend within 200 nautical miles from the baselines of another State?” is “yes”. There is nothing in the Convention to suggest otherwise.

III. JURISPRUDENCE

31. The jurisprudence of the Court and international tribunals in maritime delimitation cases supports the conclusion just reached. The Court and other tribunals have accepted that a State's entitlement to a continental shelf beyond 200 nautical miles may extend within 200 nautical miles from the baselines of another State. The Bay of Bengal cases, as well as the Court's Judgment in the Maritime Delimitation in the Indian Ocean case, are particularly relevant here.

32. In the Bay of Bengal cases, both the International Tribunal for the Law of the Sea (hereinafter “ITLOS”) and an Annex VII tribunal accepted that the parties' entitlements overlapped in the grey area. In the first Bay of Bengal case, ITLOS delimited the maritime entitlements of Bangladesh and Myanmar, including their entitlements beyond 200 nautical miles from their coasts. As the ITLOS shifted the provisional equidistance line in favour of Bangladesh, the delimitation of the continental shelf beyond 200 nautical miles involved an area located beyond 200 nautical miles from the coast of Bangladesh but within 200 nautical miles from the coast of Myanmar, yet on the Bangladeshi side of the delimitation lineFootnote ³⁸. Similarly, the arbitral tribunal's delimitation within and beyond 200 nautical miles in Bangladesh v. India involved an area lying beyond 200 nautical miles from the coast of Bangladesh and within 200 nautical miles from the coast of India, yet on the Bangladeshi side of the delimitation lineFootnote ³⁹. As a matter of delimitation, the tribunals allocated to Bangladesh an area corresponding to its continental shelf beyond 200 nautical miles that would have otherwise been areas of the continental shelf within 200 nautical miles of Myanmar and India. Thus, these decisions are premised on the finding that the parties' continental shelf entitlements could and did overlapFootnote ⁴⁰. As discussed above, this concerns the identification step (see paragraph 11 above).

33. The Court's Judgment in Somalia v. Kenya is also relevant. There, the Court accepted that Kenya's entitlement to a continental shelf beyond 200 nautical miles could extend within 200 nautical miles from Somalia's coast. In that case, the Court stated that, depending on the extent of Kenya's entitlement (as it may be established on the basis of the Commission's recommendations), the delimitation line constructed by the Court might give rise to an area “located beyond 200 nautical miles from the coast of Kenya and within 200 nautical miles from the coast of Somalia, but on the Kenyan side of the delimitation line”Footnote ⁴¹. The Court described this area as a “possible grey area” (which is depicted on sketch-map No. 12 of the Judgment as a small grey wedge)Footnote ⁴². The reason the Court used the term “possible” is plain. When the Judgment was rendered in 2021, the Commission had not issued its recommendations in respect of Kenya's submission on the continental shelf beyond 200 nautical milesFootnote ⁴³. There thus remained — at the time, but no moreFootnote ⁴⁴ — some doubt about the extent of Kenya's continental shelf entitlement beyond 200 nautical miles. That said, the Court considered that the parties' continental shelf entitlements could overlap as a matter of law.

34. That the Court so considered is also evident from the way the Court delimited the maritime boundary beyond 200 nautical miles between the parties. It did so by extending, beyond 200 nautical miles, the same geodetic line that constitutes the single maritime boundary delimiting the exclusive economic zone and the continental shelf up to 200 nautical milesFootnote ⁴⁵. The issue is this: had there been no overlapping continental shelf entitlements, the Court would have been precluded from doing so — at least initially. Somalia alone would have had a continental shelf entitlement within the wedge. The Court would have had to draw a delimitation line taking a “zig-zag” course. The Court did not do so, however. Presumably, it saw no bar in international law to delimit the maritime boundary in such a way as resulting in Kenya's continental shelf beyond 200 nautical miles extending within 200 nautical miles from the baselines of Somalia.

35. The question may be asked how these decisions differ from the present one?

36. In paragraph 72 — which is not a model of clarity — the Court's Judgment is quick to reply that these three decisions are “of no assistance”. The Judgment attempts to find safety in the suggestion that the present case differs from these decisions because Nicaragua “claims an extended continental shelf that lies within 200 nautical miles from the baselines of one or more other States” (ibid.). By contrast, says the Judgment, in the two Bay of Bengal cases, it was the “use of an adjusted equidistance line in a delimitation between adjacent States [that], as an incidental result of that adjustment, gave rise to a grey area”. Likewise, in Somalia v. Kenya, it was the use of an adjusted equidistance line that gave rise, “as an incidental result”, to a possible grey area between two adjacent States.

It is hard to know what to make of this cryptic statement. What it seems to boil down to is a distinction between States with adjacent coasts (the Bay of Bengal cases and Somalia v. Kenya) and States with opposite coasts (as in this case). It is true that an area of overlap may arise and be dealt with differently depending on the coastal configuration. When a tribunal delimits the entitlements of adjacent States both within and beyond 200 nautical miles, a grey area will arise whenever the single maritime boundary of the 200-nautical-mile entitlements departs from an equidistance line. Between States with opposite coasts, where the distance between the two coasts is greater than 400 nautical miles, and only one State has an entitlement to a continental shelf beyond 200 nautical miles — as is the case here — the grey area may have a different shape than the wedge-shaped areas seen with adjacent States. The shape and size of the grey area, if any, will vary depending on the extent of a State's entitlement to a continental shelf beyond 200 nautical miles as determined by a court or tribunal applying the rules on maritime delimitation calling for the achievement of an equitable result.

37. The Respondent insists that the grey areas of the Bay of Bengal cases and Somalia v. Kenya were merely “incidental results” of the delimitation process. This looks to me self-defeating: to suggest that they were incidental results of the delimitation is to accept that the parties' entitlements overlapped to begin with, and hence, that they can overlap as a matter of lawFootnote ⁴⁶. Again, courts and tribunals may only delimit the parties' entitlements that overlap.

The Respondent further suggests that the “small” grey areas at stake in these decisions are different from “the huge grey area that Nicaragua seeks to create in the present [case]”Footnote ⁴⁷.

This confuses the preliminary identification step with the final delimitation. I agree that, depending on the circumstances of a particular case, there may be something inequitable in allocating to broad-margin State A an area which it may claim as a continental shelf beyond 200 nautical miles but that falls within 200 nautical miles of State B. In such a hypothesis, State B could be left with a continental shelf not reaching 200 nautical miles from its coast, whereas State A would enjoy its continental shelf both up to and beyond 200 nautical miles from its coast. However, this is a matter of delimitation. The size of a grey area may have some role to play at later stages of the delimitation — for instance, as a possible circumstance relevant to an equitable solution — but it plays no role in determining whether there is an overlap of entitlements.

The coastal configuration of States — whether they are States with opposite or adjacent coasts — can have no bearing on the issue of principle whether, at the identification step, a State's continental shelf entitlement beyond 200 nautical miles may overlap with another State's entitlement to a continental shelf based on the 200-nautical miles distance criterion. The entitlement of the coastal State over the continental shelf is the same, no matter its coastal situationFootnote ⁴⁸.

Rather, if grey areas are “impossible” because legally there can be no overlapping entitlements — as today's Judgment seems to conclude in paragraph 82 — then grey areas are impossible no matter the circumstances.

38. It seems, therefore, that there is no escape from the conclusion that today's Judgment departs from the Court's jurisprudence and that of international tribunals. This jurisprudence contains a consistent finding of law which the Court simply ignores. I regret that the Court provides no convincing rationale for this departureFootnote ⁴⁹. As my distinguished colleagues observed in the past, the Court “must ensure consistency with its own past case law in order to provide predictability . . . This is especially true in different phases of the same case or with regard to closely related cases”Footnote ⁵⁰.

IV. PRACTICE OF STATES

39. I pass now to an examination of the existence of an alleged rule of customary international law that would prevent a State's entitlement to a continental shelf beyond 200 nautical miles from extending within 200 nautical miles from the baselines of another State. According to the Court's settled jurisprudence, the existence of a rule of customary international law requires that there be “a settled practice” together with opinio juris Footnote ⁵¹. Despite the importance of this question and the extensive pleadings of the Parties on this issue, it is hard to say that the Court has taken its task of identifying custom very seriously. The Court's Judgment devotes only a single paragraph to its “analysis” of this practice (Judgment, para. 77). In fact, the Judgment does not even summarize the Parties' arguments properly. I thus feel the need to give a very summary account of the Parties' legal contentions. Without being exhaustive, I shall also examine the two elements of custom below.

40. Basically, the Respondent argues that States follow a customary rule according to which natural prolongation “is not a source of title within maritime areas that lie 200 nautical miles from another State's baselines”Footnote ⁵². It refers to the practice of some 30 broad-margin States (35 States in its Counter-MemorialFootnote ⁵³, 31 States in its RejoinderFootnote ⁵⁴) which, it says, “could have potentially claimed [a continental shelf beyond 200 nautical miles from their coasts] that would have encroached upon the 200-nautical-mile entitlement of another State, but. . . stopped at the other State's 200-nautical-mile zone”Footnote ⁵⁵. This alleged body of practice mostly takes the form of 51 CLCS submissions, which Colombia compiled in an annex to its Counter-MemorialFootnote ⁵⁶.

41. This argument is not new. The Respondent made the same argument in 2012Footnote ⁵⁷.

V. ENTITLEMENT TO THE EXCLUSIVE ECONOMIC ZONE

65. There is another matter which seems to call for comment. So far, the question of the overlap of entitlements has been approached from the perspective of the continental shelf, that is, by asking whether a State's continental shelf entitlement beyond 200 nautical miles may overlap with another State's continental shelf within 200 nautical miles. I have reasoned that the answer is “yes”.

66. Another way to approach the issue is from the perspective of the exclusive economic zone. States are entitled to an exclusive economic zone of up to 200 nautical miles from the baselines from which the breadth of the territorial sea is measured. It may thus be asked whether one State's continental shelf entitlement beyond 200 nautical miles may overlap with another State's exclusive economic zone entitlement. That is: does the entitlement of a coastal State to an exclusive economic zone, encompassing the waters superjacent to the sea-bed, but also the sea-bed and its subsoil, “exclude” an entitlement by another State to a continental shelf beyond 200 nautical miles from its baselines that extends into the same area? Colombia has strenuously argued that this is so. Again, this a question of law and it arises at the identification step.

This argument is not new. The Respondent made the same argument in 2012.

67. The Court's Judgment does not squarely engage with this question, and I do not wish to dwell on it. Suffices to note that the Bay of Bengal decisions and the Court's Judgment in Somalia v. Kenya, in so far as they recognized the existence of grey areas, found that an entitlement to a continental shelf beyond 200 nautical miles may extend and overlap with an exclusive economic zone entitlement. That is the correct finding in law. The institutions of the continental shelf and the exclusive economic zone are “different and distinct”Footnote ¹⁰³. Neither nullifies — or takes “priority” over — the other to prevent an overlapFootnote ¹⁰⁴. Again, a feature of maritime entitlements is that they can overlap (see paragraph 12 above). This is true even when the entitlements are of a different natureFootnote ¹⁰⁵.

68. Paragraphs 68 to 70 of the Judgment are devoted to the relationship between the régime of the exclusive economic zone and that of the continental shelf under customary international law. Presumably, this relationship is seen by the Court as germane to answering the first question. The Court observes that the régime of the exclusive economic zone is the result of a compromise; it notes that this régime confers sovereign rights of exploration, exploitation, conservation and management of natural resources to the coastal State; it recalls that, within the exclusive economic zone, the rights with respect to the sea-bed and subsoil are to be exercised in accordance with the régime of the continental shelf. These observations are on their face unobjectionable, and I could subscribe to the Court's reasoning were it not for the fact that this reasoning seems to carry with it a veiled proposition the implications of which are not teased out in the Judgment but nonetheless significant.

69. In paragraph 70 of the Judgment the Court quotes a passage of its 1985 Judgment in the Continental Shelf (Libyan Arab Jamahiriya/Malta) case. Said passage reads as follows:

The Court does not explain why this passage of the 1985 Judgment is relevant. It draws no conclusion from its reasoning.

70. I find it hard to see the quotation of this passage as a mere happenstance. Throughout the proceedings, the Respondent has relied on this passage of the Court's Judgment in the Continental Shelf (Libyan Arab Jamahiriya/Malta) case to suggest that the Court should avoid “creating” a “huge” grey area in the present case. For Colombia, the existence of a grey area cannot be upheld in this case without calling into question the very notion of the exclusive economic zone, which, it claims, was meant to join all the physical layers of the sea under one national jurisdiction in which the coastal State would exercise sovereign rights over both the living and non-living resources (Judgment, para. 63). Colombia argues that an exclusive economic zone the water column of which is divorced from the sea-bed and subsoil, is no longer an exclusive economic zone (ibid., para. 64). To support this argument, Colombia purports to rely on the Court's “finding” in the Continental Shelf (Libyan Arab Jamahiriya/Malta) case, quoted above, that “there cannot be an exclusive economic zone without a corresponding continental shelf”Footnote ¹⁰⁶.

71. The truncated passage on which Colombia relies does not support its argument. In Continental Shelf (Libyan Arab Jamahiriya/Malta), the Court was merely stating the obvious: continental shelf exists ipso facto and ab initio Footnote ¹⁰⁷, whereas an exclusive economic zone has to be proclaimed by the coastal State. An exclusive economic zone exists only in so far as the coastal State chooses to proclaim such a zoneFootnote ¹⁰⁸. That is why “[a]lthough there can be a continental shelf where there is no exclusive economic zone, there cannot be an exclusive economic zone without a corresponding continental shelf”. That is all. This passage does not stand for the proposition that “the water column of the exclusive economic zone cannot in principle be divorced from its sea-bed and subsoil”Footnote ¹⁰⁹. This is a reading of the 1985 Judgment that its text cannot bear.

72. In any event, the Respondent's concerns against differentiating water-column rights and continental-shelf rights in a given area relate to the achievement of an equitable result. They do not concern the identification step. As mentioned above (see paragraph 19), an area of overlapping entitlements must be distinguished from the maritime area that may be established by a court or tribunal on the basis of such overlapping entitlements. It is true that in the Bay of Bengal cases, for instance, the tribunals' decisions to delimit the parties' entitlements resulted in maritime areas in which jurisdiction over the water column was adjudicated as appertaining to one State and jurisdiction over the seabed and subsoil to another. As the arbitral tribunal explained in Bangladesh v. India, “[t]he establishment of a maritime area in which the States concerned have shared rights is not unknown under the Convention”Footnote ¹¹⁰. It is also not unknown in practice. Needless to say, the Court could have arrived at this or at a different solution in its task to find an equitable solution in the present case had it proceeded to the delimitation.

I. PROCEDURAL FAIRNESS FOR THE GOOD ADMINISTRATION OF JUSTICE

2. My reservation about the procedural fairness in the organization of oral proceedings has been largely reflected in the joint declaration appended to the Order of 4 October 2022 in.the present case (Question of the Delimitation of the Continental Shelf between Nicaragua and Colombia beyond 200 Nautical Miles from the Nicaraguan Coast (Nicaragua v. Colombia), Order of 4 October 2022, joint declaration of Judges Tomka, Xue, Robinson, Nolte and Judge ad hoc Skotnikov). With this final decision settling the case, the oral proceedings on the merits were closed and, consequently, the Parties did not have an oral hearing to make their final arguments on all the issues that still divided them and to submit their final submissions to the Court. Procedurally, this practice is unprecedented in the Court's judicial history.

3. According to Article 48 of the Statute, the Court shall make orders for the conduct of the case and decide the form and time in which each party must conclude its arguments. This power, however, must be exercised in accordance with the principle of juridical propriety for the good administration of justice. Article 31 of the Rules of Court provides that “[i]n every case submitted to the Court, the President shall ascertain the views of the parties with regard to questions of procedure”. Procedurally, the Court must ensure that each party is free to choose and follow its own judicial strategy and to fully develop all its arguments. In this regard, the Court should exercise great caution when controlling the oral proceedings so as to avoid jeopardizing the rights of the parties (ibid., para. 11, note 3, citing Mohammed Bedjaoui, “The ‘Manufacture’ of Judgments at the International Court of Justice”, Pace Yearbook of International Law, 1991, Vol. 3, p. 44; Eduardo Jiménez de Aréchaga, “The Amendments to the Rules of Procedure of the International Court of Justice”, American Journal of International Law, 1973, Vol. 67 (1), p. 7).

4. In its final written pleadings, Nicaragua has made three submissions. The first submission concerns maritime delimitation between the continental shelf beyond 200 nautical miles (also referred to as the “extended continental shelf”) as claimed by Nicaragua and Colombia's maritime area within 200 nautical miles from Colombia's mainland baselines. The second and third submissions relate to the maritime entitlements of Colombia's maritime features that may overlap with Nicaragua's entitlement to an extended continental shelf. Apparently, Nicaragua's submissions concern both maritime entitlements of the Parties and delimitation. The legal questions posed by the Court in the 4 October 2022 Order primarily address the issue of entitlement. Without hearing the Parties on all the issues, both in law and in fact, and without making the entire case file accessible to the public, the judicial process did not fully run its course. This is particularly questionable when the Applicant has specifically requested the Court to proceed to a hearing on the merits.

5. Procedurally, even supposing that the answers to the legal questions were decisive for the resolution of the whole case, the present approach adopted by the Court at this phase should still be called into question. As the Applicant indicated, the legal questions posed by the Court had already been substantially argued by the Parties in the course of the written proceedings of this case and during the Territorial and Maritime Dispute (Nicaragua v. Colombia) case.

6. The first legal question posed by the Court initially arose from Nicaragua's submission I (3) in the Territorial and Maritime Dispute case, where Nicaragua requested the Court to define “a continental shelf boundary dividing by equal parts the overlapping entitlements to a continental shelf of both Parties”, which means that Nicaragua's claim to a continental shelf extends beyond 200 nautical miles, as the distance between the mainland coasts of the Parties extends more than 400 nautical miles (Nicaragua v. Colombia, Judgment, I.C.J. Reports 2012 (II) (hereinafter the “2012 Judgment”), p. 636, para. 17). The Court rejected Nicaragua's request for the delimitation of its extended continental shelf with Colombia's maritime entitlements on the ground that Nicaragua had not established that it has a continental margin that extends far enough to overlap with Colombia's 200-nautical-mile entitlement to the continental shelf, measured from Colombia's mainland coast. The Court stated that it was not in a position to delimit the continental shelf boundary between Nicaragua and Colombia, as requested by Nicaragua, even using the general formulation proposed by it (ibid., p. 669. para. 129). In this regard, the Court especially mentioned that it saw no need to address the issue raised by the Parties as to whether a delimitation of overlapping entitlements which involves an extended continental shelf of one State can affect a 200-nautical-mile entitlement to the continental shelf of another State (ibid., pp. 669-670, paras. 129-130), a legal question that the Court now considers has been answered by customary international law.

7. Moreover, during the oral proceedings in that case, Judge Bennouna posed the following questions to the Parties:

1. – “Is the legal régime of the continental shelf for the portion located within the 200-nautical-mile limit different from that for the portion located beyond this limit?”

2. – “Can the rules laid down in Article 76 of the 1982 United Nations Convention on the Law of the Sea concerning the determination of the outer limit of the continental shelf beyond 200 nautical miles today be considered as rules of customary international law?”

In answering Judge Bennouna's questions, the Parties went some way in answering the first question posed by the Court in the Order of 4 October 2022 and gave their views on the criteria under customary international law for the determination of the limit of the continental shelf beyond 200 nautical miles.

8. At the preliminary objections phase in the present case, Colombia contended that Nicaragua's first submission was a “reincarnation” of Nicaragua's claim contained in its final submission I (3) in the Territorial and Maritime Dispute case, in so far as it concerned delimitation of extended continental shelf. It argued that, by virtue of res judicata, the Court was prevented from entertaining it in the present case. The Court rejected Colombia's objections, including its claim based on res judicata, and upheld the admissibility of Nicaragua's first submission. During the written proceedings, the Parties significantly developed their arguments on Nicaragua's entitlement to an extended continental shelf and its relationship with Colombia's entitlements within 200 nautical miles.

9. From a procedural point of view, there seems to be no sound reason for the Court to depart from its established practice by holding an oral proceeding to hear the views of the Parties only on two legal questions. The Parties could have addressed them together with the factual and other legal aspects of the case during the oral proceedings on the merits. If the settlement of the dispute between the Parties on Nicaragua's entitlement to an extended continental shelf indeed hinges entirely on the answers to the legal questions, as recalled above, the matter should have been resolved much earlier for the sake of judicial economy. As a judicial organ, the Court is supposed to know the law — iura novit curia — and apply it to settle a dispute whenever it is called for. If the Court considers that, under customary international law, maritime entitlements within 200 nautical miles of one State take precedence over an extended continental shelf of another State, it should have decided, either in the 2012 Judgment in the Territorial and Maritime Dispute case or in the Judgment of 17 March 2016 on preliminary objections in the present case (hereinafter the “2016 Judgment”), that, by virtue of customary international law, Nicaragua's claim of an extended continental shelf should be rejected outright because Nicaragua is not entitled to such a claim and consequently no issue of delimitation arises between the Parties. The dispute would thus have been settled there. Having unduly prolonged the judicial process and having left unexamined all the technical and scientific evidence submitted by the Parties, the Court's approach, for whatever reason, cannot be deemed in conformity with the principles of judicial propriety and has doubtfully facilitated judicial economy.

II. SUBSTANTIVE ISSUES IN THE PRESENT CASE

10. I agree with the majority that the negotiation and conclusion of the United Nations Convention on the Law of the Sear (hereinafter “UNCLOS”) has, to a large extent, codified and contributed to the progressive development of customary international law of the sea. However, I do not share the reasoning given in the Judgment on the contemporary régime of the continental shelf. The legal issue before the Court ultimately boils down to a question that often arises in continental shelf delimitation, namely, the relationship between the extended continental shelf of one State and maritime entitlements within 200 nautical miles from the baselines of another State. It bears on the fundamental concept of natural prolongation in contemporary customary international law and the “package deal” that was negotiated and eventually worked out at the Third United Nations Conference on the Law of the Sea (hereinafter the “Law of the Sea Conference”). The reasoning of the Judgment on the current state of the law, in my view, is neither persuasive nor reflective of general State practice and opinio juris.

B. Relationship between the régimes of the continental shelf and of the exclusive economic zone

20. In recalling the negotiating history of UNCLOS, the Court refers to the relationship between the régimes of the exclusive economic zone and of the continental shelf. In the Court's view, since a coastal State enjoys in the exclusive economic zone, inter alia, sovereign rights over the non-living resources in the sea-bed and subsoil within 200 nautical miles and since such rights shall be exercised in accordance with the rules applicable to the continental shelf, the two régimes are interrelated. Based on that link, the Court assumed that the entitlement to an extended continental shelf may not extend within 200 nautical miles because such an extension would encroach on the attendant exclusive economic zone of the coastal State. This inference, in my view, overstates the import of Article 56, paragraph 3.

21. First of all, the interrelationship between the régimes of the exclusive economic zone and of the continental shelf as provided for in Article 56 does not give a prevailing effect to the exclusive economic zone over the continental shelf. While Article 56, paragraph 3, links the two zones, it does not go so far as to say that the two zones are inseparable in maritime delimitation and that maritime entitlements within 200 nautical miles by their very nature shall take precedence over an extended continental shelf entitlement. States' positions as well as their practice are divided on the question whether the two criteria under Article 76, paragraph 1, are of equal applicability or hierarchical in effect. They differ as to whether the water column and the sea-bed within 200 nautical miles may be delimited separately. Among scholars, views on the subject-matter also vary greatlyFootnote ¹. This is indeed an area that the “package deal” was ambiguous about. On the relationship between the two régimes, one analysis of Article 56, paragraph 3, is pertinent in the present context:

“The text of Article 56 (3) is a clear indication of the applicable law, which might result from the idea that the continental shelf and the EEZ are essentially dealing with different natural resources. Whereas the continental shelf confers on coastal States exclusive rights over the exploration and exploitation of the non-living resources and sedentary resources in the seabed and subsoil, the EEZ is more concerned with living resources in the water column, in particular fisheries. It is therefore in line with the functional purposes of the two regimes if the continental shelf regime applies to the seabed and subsoil, even if the area is within the reach of the EEZ.”Footnote ²

This understanding is consistent with the concept of a single continental shelf. The continental shelf régime applies to the sea-bed and subsoil irrespective of the basis of the entitlement, natural prolongation or distance. While the inclusion of the sovereign rights over the sea-bed and subsoil in the régime of the exclusive economic zone may reinforce the continental shelf entitlement within 200 nautical miles, Article 56, by its own terms, only concerns the content and exercise of substantive rights.

22. Judicial and arbitral decisions generally recognize the autonomy and distinction of the two régimes. In the present case, however, the Court draws a different reading from its 1985 Judgment in the Continental Shelf (Libyan Arab Jamahiriya/Malta) case, where the Court observed that, “[a]lthough there can be a continental shelf where there is no exclusive economic zone, there cannot be an exclusive economic zone without a corresponding continental shelf” (Judgment, I.C.J. Reports 1985, p. 33, para. 34). Based on this statement, the Court now considers that, with the distance criterion as the sole basis of entitlement of the coastal State to both the exclusive economic zone and the continental shelf within 200 nautical miles, an extended continental shelf of one State may not extend within 200 nautical miles of another State.

23. This finding, first of all, implies that, with the distance criterion applicable to both régimes, the concept of the continental shelf within 200 nautical miles has been absorbed by that of the exclusive economic zone under the contemporary law of the sea, an implication that the Court categorically rejected in the same Judgment (see ibid., p. 33, para. 33). Following the above statement cited by the Court, the Court in that case went on stating that,

“for juridical and practical reasons, the distance criterion must now apply to the continental shelf as well as to the exclusive economic zone; and this quite apart from the provision as to distance in paragraph 1 of Article 76. This is not to suggest that the idea of natural prolongation is now superseded by that of distance. What it does mean is that where the continental margin does not extend as far as 200 miles from the shore, natural prolongation . . . is in part defined by distance from the shore, irrespective of the physical nature of the intervening sea-bed and subsoil. The concepts of natural prolongation and distance are therefore not opposed but complementary; and both remain essential elements in the juridical concept of the continental shelf.” (Continental Shelf (Libyan Arab Jamahiriya/Malta), Judgment, I.C.J. Reports 1985, p. 33, para. 34; emphasis added.)

This statement shows that the interrelationship between the two régimes as defined in Article 56, paragraph 3, is not conclusive on the question that the Court is dealing with in the present case, namely, whether there is priority accorded to the entitlement within 200 nautical miles over an extended continental shelf. Moreover, the factual situation of that case is entirely different from the present one. In the former, the distance between the parties is less than 400 nautical miles, where geographical or geophysical factors could be disregarded, while in the latter, the Applicant's claim to an extended continental shelf depends on the technical and scientific evidence that may establish the existence of the natural prolongation of its land territory. Once the natural prolongation is established, the Applicant is entitled to the extended continental shelf. What the Court stated in the context of the Libyan Arab Jamahiriya/Malta case did not address the question of entitlement but of delimitation. At the time of that case, with UNCLOS not yet in force and the customary status of Article 76, paragraph 1, with regard to the distance criterion still in doubt, the Court took the legally permissible extent of the exclusive economic zone appertaining to a given State as “one of the relevant circumstances to be taken into account for the delimitation of the continental shelf” of that State (ibid., p. 33, para. 33; emphasis added). By granting greater importance to the element of distance, which is common to both régimes, in the delimitation of continental shelf within 200 nautical miles, the Court only tried to reach an equitable solution but not to pronounce a general rule restricting natural prolongation.

24. Even supposing that the Court's statement in the Continental Shelf (Libyan Arab Jamahiriya/Malta) case did constitute a general legal pronouncement, one may still wonder when the putative rule as identified by the Court in this case formed part of customary international law, because the judicial and arbitral decisions and State practice on the delimitation of continental shelf subsequent to the 1985 Judgment do not support such a proposition.

25. In the Bay of Bengal cases, the International Tribunal for the Law of the Sea (ITLOS) and the arbitral tribunal established under Annex VII of UNCLOS respectively delimited the maritime boundary including the extended continental shelf between the parties to each case. The adjustment of the provisional equidistance line resulted in a “grey area” of limited size in both cases, which is located within the 200-nautical-mile limit of the coast of one party but on the other party's side of the line that delimits the parties' continental shelves (Delimitation of the maritime boundary in the Bay of Bengal (Bangladesh/Myanmar), Judgment, ITLOS Reports 2012, p. 119, para. 463; Bay of Bengal Maritime Boundary Arbitration between Bangladesh and India, Award of 7 July 2014, RIAA, Vol. XXXII, p. 147, para. 498). The Court dismisses the Applicant's argument based on these cases, which it considers irrelevant for the consideration of the present case, because, in its view, the grey area is “an incidental result” of the adjustment of the provisional equidistance line and the circumstances in those cases are distinct from the situation in the present case (Judgment, para. 72).

26. In Somalia v. Kenya — a case it has recently adjudicated — the Court observed that if the delimitation line, as determined, continues on the course beyond 200 nautical miles, it might give rise to an area of limited size lying within 200 nautical miles of the coast of Somalia but on the Kenyan side of the boundary, thus resulting in a similar “grey area” as in the Bay of Bengal cases (Maritime Delimitation in the Indian Ocean (Somalia v. Kenya), Judgment, I.C.J. Reports 2021, p. 277, para. 197). The Court again dismisses the relevance of the case, stating that the grey area is merely a possibility and that, therefore, there is no need to take it into account (Judgment, para. 73).

27. This approach taken by the Court appears hasty and evasive. In these three cases, the “grey area”, albeit incidental in nature and small in size, is in itself a piece of hard evidence that disproves at least the inseparability of the two zones in the maritime delimitation. Convenient or not, it evinces that the exclusive economic zone does not dictate the delimitation of the continental shelf. As ITLOS observed in the Bangladesh/Myanmar case,

“the legal regime of the continental shelf has always coexisted with another legal regime in the same area. Initially that other regime was that of the high seas and the other States concerned were those exercising high seas freedoms. Under the Convention, as a result of maritime delimitation, there may also be concurrent exclusive economic zone rights of another coastal State.” (Delimitation of the maritime boundary in the Bay of Bengal (Bangladesh/Myanmar), Judgment, ITLOS Reports 2012, p. 121, para. 475.)

Evidently, these judicial and arbitral organs do not consider that there existed a customary rule by which an extended continental shelf of one State may not extend within the exclusive economic zone of another State, as a matter of entitlement. When an overlap of entitlements occurs, the matter is one of delimitation. Article 83 of UNCLOS, on purpose, leaves sufficient room for the relevant circumstances of each case to be considered in the delimitation process.

28. In practice, States not only claim an entitlement to an extended continental shelf that may extend within 200 nautical miles of another State, but also draw maritime boundaries by agreement that delimit the exclusive economic zone and the continental shelf separately. They do it either by separate agreements dealing with different zones, or simply by drawing different boundary lines within the same agreement.

29. Australia and Indonesia, for example, concluded an agreement on the continental shelf boundary in the Timor and Arafura Seas in 1972 (Agreement between the Government of the Commonwealth of Australia and the Government of the Republic of Indonesia establishing certain seabed boundaries in the area of the Timor and Arafura Seas, supplementary to the Agreement of 18 May 1971, concluded 9 October 1972, entered into force 8 November 1973, United Nations, Treaty Series (UNTS), Vol. 974, p. 319). In 1997, the two States concluded another agreement on the exclusive economic zone boundary and the western extension of the sea-bed boundary (Agreement between the Government of Australia and the Government of the Republic of Indonesia establishing an exclusive economic zone boundary and certain seabed boundaries, concluded 14 March 1997, not yet in force, International Legal Materials, 1997, Vol. 36, p. 1053). The latter agreement drew the continental shelf boundary on the basis of the geological and geophysical factors of the Timor Trough, while the boundary of the exclusive economic zone was drawn on the basis of distance; the former line is closer to the Indonesian side. As a result of these two agreements, there are several overlapping areas where Australia's extended continental shelf is subjacent to Indonesia's exclusive economic zone (see illustrative map 1). For the purpose of management, the Agreement contains a specific provision regulating, inter alia, the rights and obligations of each party in the areas of overlapping jurisdiction. It affirms Indonesia's sovereign rights of exclusive economic zone in the water column and Australia's sovereign rights of continental shelf in the sea-bedFootnote ³. Although the Agreement has not yet entered into force, it manifests that the parties did not consider there existed a customary rule by which Australia could not, by law, claim its entitlement to an extended continental shelf that extends within Indonesia's 200 nautical miles from its baselines.

Illustrative map 1

(reproduced from Department of State of the United States of America, “Limits in the Seas (No. 141) ― Indonesia: Archipelagic and other Maritime Claims and Boundaries“, September 2014Footnote ⁴)

30. The agreement on maritime boundaries concluded between Australia and Papua New Guinea is another example (Treaty between Australia and the Independent State of Papua New Guinea concerning sovereignty and maritime boundaries in the area between the two countries, including the area known as Torres Strait, and related matters, concluded 18 December 1978, entered into force 15 February 1985, UNTS, Vol. 1429, p. 207). Under Article 4 of this Treaty, two maritime boundaries are established between the two States. The first line is the continental shelf boundary concerning “seabed jurisdiction”, which is defined as “sovereign rights over the continental shelf in accordance with international law, and includes jurisdiction over low-tide elevations, and the right to exercise such jurisdiction in respect of those elevations, in accordance with international law”Footnote ⁵. The second line is the boundary relating to fisheries jurisdiction, defined as “sovereign rights for the purpose of exploring and exploiting, conserving and managing fisheries resources other than sedentary species”Footnote ⁶. Based on the co-ordinates of the two boundaries, it is shown that, while the two boundaries in the eastern and western sections coincide, the two boundaries are separate in the middle section in the area known as the Torres Strait (see illustrative map 2). Papua New Guinea, like Indonesia, accepted Australia's position without any reservation. This treaty remains in force to date.

Illustrative map 2

(reproduced from Department of Foreign Affairs and Trade of Australia, “Guidelines for Traditional Visitors Travelling under the Torres Strait Treaty”Footnote ⁷)

31. Australia reiterated its position on the natural prolongation criterion during the Timor Sea Conciliation with Timor-Leste on the basis of Article 76, paragraph 1, of UNCLOS in light of the geological and geomorphological situation of the Timor Trough in the Timor Sea (Timor-Leste v. Australia, Permanent Court of Arbitration, Case Number 2016-10, Opening Session Transcript, 29 August 2016, p. 91). Although the parties ultimately reached a delimitation agreement establishing a single maritime boundary for both the exclusive economic zone and the continental shelf, the Preamble of the Treaty expressly states that “the settlement contained in this Treaty is based on a mutual accommodation between the Parties without prejudice to their respective legal positions” (Treaty between the Democratic Republic of Timor-Leste and Australia establishing their maritime boundaries in the Timor Sea, concluded 6 March 2018, entered into force 30 August 2019, [2019] Australian Treaty Series 16; emphasis added).

32. A more recent example is the delimitation agreement between Indonesia and the Philippines concerning the delimitation of the exclusive economic zone in the Celebes Sea concluded in 2014 (Agreement between the Government of the Republic of Indonesia and the Government of the Republic of the Philippines concerning the delimitation of the exclusive economic zone boundary, concluded 23 May 2014, entered into force 1 August 2019, UNTS, Vol. 3324, p. 1). The distance between the parties in the area in the Celebes Sea is less than 400 nautical miles. In delimiting the boundary of exclusive economic zones between the two States, the parties took account of the provisions of UNCLOS and the principles applicable to delimitation. The Agreement specifically provides that “[t]his Agreement shall not prejudice any rights or positions of the Contracting Parties with regard to the delimitation of the Continental Shelf boundary”Footnote ⁸. Apparently, the parties to the Agreement do not consider that the boundary of the exclusive economic zone is decisive for the delimitation of the continental shelf boundary within 200 nautical miles.

33. Similar practice can also be found in other regions. Denmark and the United Kingdom, for instance, reached an agreement on the maritime delimitation in the area between the Faroe Islands and the United Kingdom in 1999 (Agreement between the Government of the Kingdom of Denmark together with the Home Government of the Faroe Islands, on the one hand, and the Government of the United Kingdom of Great Britain and Northern Ireland, on the other hand, relating to the Maritime Delimitation in the area between the Faroe Islands and the United Kingdom, concluded 18 May 1999, entered into force 21 July 1999, United Kingdom Treaty Series (UKTS), 1999, No. 76). Under the Agreement, the parties delimited the continental shelf in the area and the waters superjacent to the continental shelf in part of the area and established a special régime, called “the Special Area”, in the remaining part. The parties made special arrangements for the exercise of fisheries jurisdiction and rights in the Special Area. In a subsequent protocol concluded in 2012 to the Agreement, the parties established exclusive economic zones in the waters as previously delimited and decided to retain the previous boundaries and the Special Area as drawn in the Agreement (UKTS, 2014, No. 22). From the maritime boundary shown in illustrative map 3 reproduced below, one can see that the Special Area as a water column is separated from the continental shelf of either party.

Illustrative map 3

(found in Jonathan I. Charney and Robert W. Smith (eds.), International Maritime Boundaries, 2002, Vol. IV, p. 2955)

34. There are other bilateral maritime delimitation agreements, where one party's extended continental shelf overlaps with the exclusive economic zone of another party (see Agreement between the United States of America and the Union of Soviet Socialist Republics on the maritime boundary, concluded 1 June 1990, applied provisionally since 1 June 1990, Law of the Sea Bulletin, No. 17, April 1991, p. 15; Treaty between the Kingdom of Norway and the Russian Federation concerning maritime delimitation and cooperation in the Barents Sea and the Arctic Ocean, concluded 15 September 2010, entered into force 7 July 2011, Law of the Sea Bulletin, No. 77, 2012, p. 24)Footnote ⁹.

35. In support of its claim, the Respondent refers to Article 2, paragraph 3, of the Treaty between the Federated States of Micronesia and the Republic of Palau concerning maritime boundaries and cooperation on related matters, which provides that “no Party shall claim an extended continental shelf that intrudes into the Exclusive Economic Zone . . . of the other Party” (concluded 16 July 2006, entered into force 16 February 2016, UNTS, Vol. 3210, p. 1). This evidence, contrary to the position of the Respondent, proves that these two States do not consider that there is a customary rule that prohibits an extended continental shelf from extending within 200 nautical miles from the coast of another State, because otherwise such a clause would be unnecessary.

36. Admittedly, States may make special arrangements through bilateral agreements, not necessarily guided by generally applicable law. Nonetheless, such practice supports the settled jurisprudence that the régimes of the exclusive economic zone and of the continental shelf, though interrelated, are distinct and may be delimited separately. Although a single maritime boundary is generally preferred for the convenience of management, that rationale for the delimitation does not have a restrictive effect on the entitlement to the extended continental shelf.

III. NICARAGUA'S SUBMISSIONS ON AN EXTENDED CONTINENTAL SHELF

50. Having considered the state of the law, I am of the view that Nicaragua is entitled to an extended continental shelf, provided the existence and outer limit of its continental margin is proven. As a precondition for delimitation, Nicaragua has to first prove that its continental margin overlaps with the entitlements of Colombia. For that purpose, the technical and scientific evidence adduced by the Parties must first be examined.

51. Procedurally, the expert reports produced by the Parties were not further examined at the oral proceedings because of the way in which the hearing was organized. From the written pleadings, technical and scientific evidence produced by Nicaragua seems to prove that its continental shelf, the Nicaraguan Rise, extends far enough to reach within 200 nautical miles from the mainland coast of Colombia. At the same time, however, Colombia's expert reports, in challenging the information contained in Nicaragua's submission to the CLCS with regard to the edge of the natural prolongation of the Nicaraguan land territory in the Caribbean Sea, also seem technically tenable. Without hearing from the Parties on those reports and without the assistance of experts appointed by the Court, it is difficult to assess the weight of each piece of evidence. This underscores the value and indispensability of the recommendations from the CLCS. In hindsight I believe that, in such a technically complicated case, it is a necessity for the parties to obtain the recommendations of the CLCS before proceeding to delimitation.

52. Notwithstanding my serious reservations regarding the reasoning of the Court, there are two major considerations that led me to vote in favour of the Court's decision.

53. As a technical matter, the Parties are deeply divided over the scientific and technical facts of Nicaragua's extended continental shelf. Nicaragua claims that the Nicaraguan landmass extends eastwards underwater to form the dominant feature in the southwest Caribbean: the Nicaraguan Rise, which is said to stretch over 500 nautical miles from the Nicaraguan landmass in the southwest to Jamaica and Haiti in the northeast. The Nicaraguan Rise, as is shown, is separated from the oceanic abyssal plain of the Colombian Basin to the south by a linear feature: the Hess Escarpment. Its northern edge is formed by the Cayman Trough, a deep ocean trench lying to the north of Honduras, running between Guatemala and the north coast of Jamaica, approximately parallel to the Hess Escarpment. Nicaragua further asserts that the Nicaraguan Rise is divided into two halves: to the north the Nicaraguan Rise proper and — separated from it by the Pedro Bank Fracture Zone — the Lower Nicaraguan Rise to the south. The Nicaraguan Rise is about 150 nautical miles wide (i.e. north-south) and extends from the land territory of Nicaragua in the west to Haiti in the east.

54. Contesting Nicaragua's claim, Colombia's expert reports present the analyses of the scientific evidence collected from public sources and the Colombian Navy on the natural prolongation of the sea-bed and subsoil from the Nicaraguan land territory into and under the Caribbean Sea. The key finding of the reports which is relevant to the present case is that the edge of the natural prolongation of the Nicaraguan land territory in the Caribbean Sea is not the Hess Escarpment (the southern limit of the Nicaraguan Rise as assumed by the Applicant), but the Pedro Bank Escarpment-Providencia Trough Lineament, which separates the southern edge of the Nicaraguan Rise proper from the Lower Nicaraguan Rise. According to Colombia's experts, the scope of Nicaragua's continental margin is much smaller than Nicaragua's experts suggest and, consequently, Nicaragua's landmass does not extend within 200 nautical miles from the mainland coast of Colombia.

55. The technical characterization of Nicaragua's continental margin must be left to scientific and technical experts. Divergent as they are, the expert reports of the Parties, at the least, inform the Court of some basic facts that are crucial for the consideration of Nicaragua's submissions to the Court for adjudication in the present case.

56. First, the relationship between Nicaragua's continental margin and Colombia's mainland coast remains highly uncertain. Even relying on Nicaragua's evidence, the outer limit of the Lower Nicaraguan Rise in the north-east, as defined by Nicaragua, seems overexpansive. The materials submitted by Nicaragua are not sufficient for the Court to ascertain whether and to what extent Nicaragua's continental shelf extends within 200 nautical miles of Colombia.

57. Additionally, the Court has never dealt with such a case where the delimitation involves the extended continental shelf of only one party. Even assuming that the Nicaraguan Rise is southbound by the Hess Escarpment, as asserted by Nicaragua, and that Nicaragua's entitlement is established and overlaps with Colombia's entitlements within 200 nautical miles from its mainland coast, the question nevertheless remains as to what methodology the Court should adopt to delimit the boundary between the Parties in the area. It seems highly problematic to apply the three-stage delimitation methodology that is usually used for maritime delimitation within 200 nautical miles; the relevant considerations for achieving an equitable solution may be quite different in the present situation.

58. Moreover, the Court should not lose sight of the overall geographical context in which Nicaragua's purported continental shelf is located. As is shown on the maps presented by the Parties, situated on the Nicaraguan Rise, alongside Nicaragua, are Colombia's Archipelago of San Andrés, Providencia and Santa Catalina, Jamaica and Haiti. In the western Caribbean, there is Jamaica to the north and Panama to the south. Notwithstanding the existing delimitation treaties between each of these States and Colombia, which are not opposable to Nicaragua, res inter alios acta, the entitlements of those States to a continental shelf within 200 nautical miles would likely overlap with any extended continental shelf Nicaragua may have. Therefore, it is doubtful that any extended continental shelf that Nicaragua might have established could be given its full effect to the extent that Nicaragua claims. As between the Parties, it is Colombia's islands that are situated in the middle of the mainland coasts of the two States that prove crucial for the delimitation between the Parties.

59. In the 2012 Judgment, the Court clearly did not delimit the maritime area eastward beyond the relevant area as identified for the delimitation of the maritime boundary between the Parties within 200 nautical miles from the mainland coast of Nicaragua (Territorial and Maritime Dispute (Nicaragua v. Colombia), ICJ Reports 2012 (II), p. 683, para. 159). In rejecting Nicaragua's proposal to draw a series of enclaves around each of Colombia's islands, the Court underscored the requirement not to produce cut-off effect in the delimitation. It considered, in particular, that

The Court, by implication, recognized that Colombia's islands are entitled to their continental shelves under customary international law. In the present case, should Nicaragua's second and third submissions — similar to the request Nicaragua had made in the Territorial and Maritime Dispute case — be upheld, it would produce a cut-off effect between the islands and the mainland of Colombia. Indeed, it would not be conducive to an orderly management of the maritime area and a coherent relationship among the coastal States in the western Caribbean. As Colombia's islands in the east face the mainland coast of Colombia, their entitlements to an exclusive economic zone and continental shelf should be given full effect. Furthermore, they are situated on the landmass constituting part of the continental shelf claimed by Nicaragua. Under the circumstances, it is questionable whether Nicaragua could still make a good case for its claim.

60. Based on the foregoing considerations, I come to the conclusion that Nicaragua's submissions should not be upheld.

(Signed)   XUE Hanqin.

GENERAL CONSIDERATIONS

1. Much of law is about reasonableness. The unreasonableness in the approach of the majority is revealed in their conclusion that “even if a State can demonstrate that it is entitled to an extended continental shelf, that entitlement may not extend within 200 nautical miles from the baselines of another State” (Judgment, para. 81). Thus, even if a State establishes that its outer continental shelf meets the criteria for natural prolongation, according to the majority it cannot benefit from the full extent of its shelf — that is, it cannot extend within 200 nautical miles of the baselines of another StateFootnote ¹. Ordinarily, a coastal State would benefit from the full extent of such a shelf, subject, of course, to the application of Article 83 on maritime delimitation. The proposition in paragraph 81 is an extraordinary one, and it finds no support in the 1982 United Nations Convention on the Law of the Sea (UNCLOS) or in customary international law; it strikes a jangling, discordant note in the otherwise harmonious relationship between the various maritime zones in the law of the sea. Regrettably, the majority judgment fails to substantiate its proposition, which assumes that a coastal State's 200-nautical-mile exclusive economic zone (EEZ) with its attendant distance-determined continental shelf has priority over another State's outer continental shelf based on natural prolongation. In that regard, it is to be noted that Article 77 of the Convention, which reflects customary international law, in setting out the rights of the State over the continental shelf, does not distinguish between a shelf that is based on natural prolongation and a shelf that is distance-determined. A coastal State enjoys the same sovereign rights in respect of its continental shelf, whether in relation to a natural prolongation-determined shelf or a distance-determined shelf. The relevant provisions of UNCLOS are set out in the Annex to this opinion. It is important to note that these provisions reflect customary international law; they are applicable in the current case because, unlike Nicaragua, Colombia is not a party to UNCLOS.

2. The Judgment does not establish that, under customary international law, there is a hierarchical relationship between continental shelf entitlements based on the criteria of natural prolongation and distance set out in Article 76 (1) of the Convention. The majority's negative response to the first question requires a demonstration that there is an intrinsic, inherent limitation on the extent of a State's continental shelf entitlement based on the criterion of natural prolongation. Under customary international law, there is no inherent limitation on the extent of a State's continental shelf beyond 200 nautical miles such that it cannot extend into a neighbouring coastal State's exclusive economic zone with its attendant continental shelf. In effect, the Judgment has denied a coastal State the full benefit of the natural prolongation criterion in Article 76 (1) of the Convention, which reflects customary international law. The position taken by the majority is all the more strange given that in the Tunisia/Libya case, the Court concluded that “[a]ccording to the first part of paragraph 1 the natural prolongation of the land territory is the main criterion” (Continental Shelf (Tunisia/Libyan Arab Jamahiriya), Judgment, I.C.J. Reports 1982, p. 48, para. 47). It must be emphasized, however, that, in that case, the Court did not suggest that there was a hierarchy between the criterion of natural prolongation and the criterion of distance.

3. The Judgment fails to identify any quality or element in title to a distance-determined continental shelf that would make it prevail over title to a shelf based on natural prolongation.

4. In Guinea/Guinea-Bissau, the question of the relationship between the two criteria in Article 76 was considered. In that case, speaking of the distance criterion in Article 76 (1), the tribunal held that

What is significant here is that the tribunal emphasizes that the distance criterion does not derogate from the rule of natural prolongation, and then states that there are “therefore two rules between which there is neither priority nor precedence” (ibid., para. 116). It is, of course, true that this decision did not address the precise circumstances of the present case. However, the statement of law that there is neither priority nor precedence between the two criteria is, in principle, beyond question.

5. Since, under Article 76 of UNCLOS, title to a continental shelf based on natural prolongation is co-equal with title to a continental shelf based on distance, a continental shelf based on natural prolongation that overlaps with a shelf based on distance is as amenable to delimitation as overlapping continental shelves based on natural prolongation or distance. Indeed, there is scholarly writing that Article 83 on the delimitation of the continental shelf “confirms that no distinction is made between the continental shelf within and beyond 200 nautical miles” (see Xuexia Liao, “Is There a Hierarchical Relationship between Natural prolongation and Distance in the Continental Shelf Delimitation?”, International Journal of Marine and Coastal Law, 2018, Vol. 33 (1), pp. 79-115); certainly, there is nothing in Article 83 to indicate that it is not applicable to the delimitation of the maritime boundary between the continental shelf of a coastal State beyond 200 nautical miles from the relevant baselines and the continental shelf of another State within 200 nautical miles from the relevant baselines. Indeed, the Convention must be seen as proceeding on the basis of co-equality between title to a continental shelf based on natural prolongation and title based on distance. Since there is co-equality, one title cannot extinguish the other title because both titles have the same valency; consequently, there may be an overlap, in which case maritime delimitation under Article 83 comes into play. More generally, this is also true of the relationship between the maritime zone of one State and a similar maritime zone of another State. Thus, the exclusive economic zone of State A has the same valency as the exclusive economic zone of State B, to which it is adjacent or opposite. The law of the sea is so configured that a coastal State benefits from the full extent of its maritime zones — whether territorial sea, exclusive economic zone or continental shelf, to name a few — subject, of course, to maritime delimitation. The principle of co-equality of maritime zones is a necessary feature of the Convention, whose aim is to establish, “with due regard for the sovereignty of all States, a legal order for the seas and oceans” (UNCLOS, preamble). Co-equality of maritime zones, an assumption of the Convention, gives rise to overlapping entitlements which call for maritime delimitation. The approach of the majority is antithetical to maritime delimitation, a tool essential for the “legal order for the seas and oceans”, because that approach sees title to the maritime zone of one State extinguishing title to a similar maritime zone of another State.

6. The Judgment in paragraph 58 cites Nicaragua's submission that the decision in the Bay of Bengal cases means that a grey area is created in which the two States “must co-operate” (Delimitation of the Maritime Boundary in the Bay of Bengal (Bangladesh/Myanmar), Judgment, ITLOS Reports 2012, pp. 64-68, paras. 225-240; Bay of Bengal Maritime Boundary Arbitration (Bangladesh v. India), Award of 7 July 2014, RIAA, Vol. XXXII, pp. 104-106, paras. 336-346). It is true that this result is untidy since one State has sovereign rights over the superjacent waters while another State has sovereign rights over the sea-bed. However the obligation to co-operate should not be undervalued. It should not be overlooked that Article 1, paragraph 3, of the Charter of the United Nations provides that one of the purposes of the United Nations is “to achieve international cooperation in solving international problems of an economic, social, cultural, or humanitarian character”. Indeed, in 1945, one of the great hopes of the international community was that after the atrocities of the Second World War, the era of national sovereignty would be replaced by an era of international co-operation.

7. The Judgment refers to Colombia's submissions emphasizing that the EEZ was the result of a compromise reached at the Conference and which took into account proposals by developing Latin American and African countries. Colombia is correct in outlining the general features of the EEZ, which is neither territorial sea nor high sea, but in which the coastal State has exclusive sovereign rights over the living and non-living resources. The Judgment cites Colombia as contending “that an exclusive economic zone the water column of which is divorced from the sea-bed and subsoil is no longer an exclusive economic zone” (para. 64). However, by the same token, it could be said that a continental shelf that may not extend within 200 nautical miles of the baselines of another State, even though it satisfies the scientific criteria for natural prolongation, is no longer a continental shelf. Moreover, although the concept of the EEZ emanated from developing States, it was not part of the bargain that they would surrender the benefits of an outer continental shelf based on natural prolongation; the bargain was that, in respect of the exploitation of the non-living resources of the continental shelf beyond 200 nautical miles, a payment would be made to the International Seabed Authority (ISA) to be distributed to States parties to the Convention, taking into account the needs of developing States, on the basis of equitable sharing criteria (see UNCLOS, Article 82).

8. The majority advance two main arguments for the conclusion that “under customary international law, a State's entitlement to a continental shelf beyond 200 nautical miles from the baselines from which the breadth of its territorial sea is measured may not extend within 200 nautical miles from the baselines of another State” (Judgment, para. 79). The first main argument is that, under customary international law, there is a rule prohibiting a State's outer continental shelf from extending within 200 nautical miles from the baselines of another State.

THE FIRST MAIN ARGUMENT: THERE IS A RULE OF CUSTOMARY INTERNATIONAL LAW

9. In the 1969 North Sea Continental Shelf cases, the Court held that customary international law had two elements: extensive and virtually uniform practice, and opinio juris. The International Law Commission (ILC), the United Nations body charged with the responsibility of the codification and progressive development of international law, has concluded that these two elements must be separately determined (see the ILC's 2018 Draft conclusions on identification of customary international law, Conclusion 3, paragraph 2), no doubt to guard against the temptation of simply snatching opinio juris from practice. Paragraph 8 of the ILC's draft Commentary on its Conclusion 3 emphasizes that “the existence of one element may not be deduced merely from the existence of the other”; but, in the circumstances of this case, this is precisely what the Judgment does: it deduces opinio juris merely from the existing practice of 39 States.

10. In the Lotus case, the Permanent Court of International Justice (PCIJ) found that the practice of abstention was, by itself, not sufficient to constitute customary international law; it was necessary to provide separately evidence of opinio juris, that is evidence that the practice was prompted by a sense of legal obligation (see “Lotus”, Judgment No. 9, 1927, P.C.I.J., Series A, No. 10, p. 28). In the words of the PCIJ, “for only if such abstention were based on [States] being conscious of having a duty to abstain would it be possible to speak of an international custom” (ibid., p. 28). There can be no presumption that a State's abstention is motivated by a legal obligation. Even if there is such a presumption, it must be one that is rebuttable. In the circumstances of this case, any presumption of opinio juris is rebutted by the very clear possibility, as set out below, that the practice of self-constraint may be explained by considerations other than a sense of legal obligation.

11. Against this background, the opinion now proceeds to examine, first, the evidence relating to State practice and, secondly, the evidence relating to opinio juris.

12. Article 76, paragraph 7, requires the coastal State to delineate the outer limits of its continental shelf beyond 200 nautical miles from the baselines from which the breadth of the territorial sea is measured. Article 76, paragraph 8, requires the coastal State to submit to the Commission on the Limits of the Continental Shelf (CLCS or the Commission) information on the limits of its continental shelf beyond 200 nautical miles from the baselines from which the breadth of the territorial sea is measured. The evidence before the Court is that 55 submissions have been made to the CLCS in which coastal States could have, on geological or geomorphological grounds, extended their continental shelves within the 200-nautical-mile zones of other States; of that number, 51 submissions made by 39 States refrained from asserting limits that extended within 200 nautical miles of the baselines of another State.

13. It is acknowledged that there is a basis for the Court's conclusion that, “[t]aken as a whole, the practice of States may be considered sufficiently widespread and uniform for the purpose of the identification of customary international law” (Judgment, para. 77). This is so because the evidence shows that of 43 States that could have claimed an outer continental shelf that extends within 200 nautical miles of the baselines of another State, 39 have chosen not to so extend their shelves. There is therefore practice that can be considered sufficiently widespread and uniform. However, the reasoning in the Judgment completely breaks down in relation to the element of opinio juris.

14. The Court found that the practice before the CLCS “is indicative of opinio juris, even if such practice may have been motivated in part by considerations other than a sense of legal obligation” (ibid.). This conclusion is unsafe, because the possibility that the practice was motivated by considerations other than a sense of legal obligation permeates and infects that practice in its entirety, thereby disabling it from constituting opinio juris. The Court has before it very little, if any, specific or direct evidence of opinio juris. This element will, as is most usually the case, be determined inferentially from all the relevant circumstances. In the absence of clear evidence to the contrary, it is simply impossible in this case to separate practice that is properly motivated by a sense of legal obligation from practice that is not so motivated. Nicaragua has submitted that the self-constraint of States “is motivated by considerations other than a sense of legal obligation, in particular a desire to avoid the possibility of their submission giving rise to a dispute with the result that the Commission would not consider it” (Judgment, para. 57). Indeed, Nicaragua points out that not even one CLCS submission “states directly or even indirectly that they refrain from encroaching into the EEZ of third States because the EEZ has priority over any claim of an extended continental shelf”Footnote ². It also points out that, in respect of the protests filed in relation to the CLCS submissions of the four States that claim an outer continental shelf within 200 nautical miles of the baselines of another State, “not a single one of the protests has alleged that there was a rule of customary international law that automatically gave priority to the EEZ or 200 [nautical miles] continental shelf of one [S]tate over the extended continental shelf of another, or extinguished such overlapping extended continental shelf claims”Footnote ³.

15. The CLCS procedure set out in paragraph 8 of Article 76 of the Convention has special significance for the coastal State. Under that paragraph, after the Commission has received the information submitted to it by the coastal State, it makes recommendations on matters related to the establishment of the outer limits of the continental shelf. In accordance with the last sentence of paragraph 8, the “limits of the shelf established by a coastal State on the basis of these recommendations shall be final and binding”. Every coastal State would wish to be in a position to establish limits of the shelf that are final and binding. Every coastal State, therefore, has an incentive to ensure that it does not take any action that would prevent the Commission from making recommendations on the basis of the information that it has submitted to the Commission. One such action that would have that result is addressed by Article 5 (a) of Annex I of the Rules of Procedure of the CLCS, which reads: “In cases where a land or maritime dispute exists, the Commission shall not consider and qualify a submission made by any of the States concerned in the dispute.”

16. It is therefore likely that the reason for the States' self-constraint is the very real possibility that the claim to an outer continental shelf which extends within 200 nautical miles of the baselines of another State would lead to a protest, giving rise to a dispute, thereby preventing the Commission from qualifying or considering the coastal State's submission. We know that this has happened to the four States that have claimed such an extension. There were protests; in accordance with Article 5 (a) of Annex 1 of the Rules of Procedure of the CLCS, their submissions would not have been processedFootnote ⁴.

17. The possibility that the self-constraint is explicable by other than legal considerations is, therefore, very live in the circumstances of this case, and it is a possibility that affects every single claim made by the 39 States. It is not confined, as the Judgment claims, to a part of those claims because the entirety of the claims may have been motivated by considerations other than a sense of legal obligation. Moreover, it is notable that in describing Nicaragua's submission, in paragraph 57 of the Judgment, the Court uses the language “in particular a desire to avoid the possibility of their submission giving rise to a dispute with the result that the Commission would not consider it” (emphasis added). Thus, there might have been other examples of a situation in which the submission to the CLCS was motivated by considerations other than a sense of legal obligation. Notably, although the Judgment in paragraph 57 makes reference to Nicaragua's submission, nowhere in its later analysis (see paragraphs 68-79) does it address that submission.

18. The Judgment places great reliance on the Gulf of Maine case to support its conclusion that

However, the Judgment does not quote the sentence from the Gulf of Maine Judgment in full. The last eight words have been omitted: “and not by deduction from preconceived ideas”.

19. The context in which the dictum in Gulf of Maine was made is completely different from the present case. Gulf of Maine was decided in 1984, a time when customary rules of the law of the sea were not as developed as they are now. In that case, the Court criticized the parties for adopting positions that reflected an a priori and preconceived approach rather than a “convincing demonstration of the existence of the rules that each had hoped to find established by international law” (Delimitation of the Maritime Boundary in the Gulf of Maine Area (Canada/United States of America), Judgment, I.C.J. Reports 1984, p. 298, para. 109). There is nothing novel or startling in the Court's approach in the Gulf of Maine case; it is supported by common sense, as an empirical approach is generally to be preferred over one based on a priori, preconceived notions. One does not need to have recourse to the Gulf of Maine dictum as authority for the proposition that opinio juris may be derived from extensive and convincing State practice. The Court's Judgment is open to criticism because in the particular circumstances of this case there is no basis for deriving opinio juris from State practice relied upon.

20. If the Gulf of Maine dictum is to apply in this case, the State practice relied on will only be seen as an expression of opinio juris if it is “sufficiently extensive and convincing”. The practice of 39 States, even if sufficiently extensive, will not establish the element of opinio juris, for the reason that it is not convincing. Practice which may be motivated by considerations other than a sense of legal obligation, as is the case here, can scarcely be described as convincing. Consequently, the Gulf of Maine dictum is not helpful to the majority.

THE SECOND MAIN ARGUMENT: ARTICLE 82 WILL LOSE ITS RAISON D'ÊTRE

21. The second main argument advanced by the majority for its approach is that Article 82 would lose its meaning, if not its raison d'être, if the entitlement of a State to an outer continental shelf were allowed to extend within 200 nautical miles of the baselines of another State (Judgment, para. 76). Article 82 was part of the compromise reached in the UNCLOS negotiations for a definition of the continental shelf that would incorporate continental shelves beyond 200 nautical miles from the baselines from which the breadth of the territorial sea is measured. The wide-margin States insisted on such a definition. However, Article 82 reflects the price that was paid by those States for that concession. The title of Article 82 is: “Payments and contributions with respect to the exploitation of the continental shelf beyond 200 nautical miles”. Paragraph 1 of Article 82 provides:

There is nothing in either the title or in paragraph 1 that prohibits payments in respect of the exploitation of the non-living resources of the continental shelf beyond 200 nautical miles when a coastal State's outer continental shelf extends within 200 nautical miles of another State. The only requirement of Article 82 is that the exploitation must relate to non-living resources of the continental shelf beyond 200 nautical miles from the baselines from which the breadth of the territorial sea is measured. It is incorrect to assert, as the majority does in paragraph 76 of the Judgment, that the payment would not serve the purpose of this provision in a situation where the outer continental shelf of one State extended within 200 nautical miles from the baselines of another State. A plain reading of the title and paragraph 1 of Article 82 makes it clear that the payment is due whenever and wherever there is exploitation of the non-living resources of the continental shelf beyond 200 nautical miles from the baselines from which the breadth of the territorial sea is measured; in all such cases, the payments are “made through the Authority, which shall distribute them to States Parties to this Convention, on the basis of equitable sharing criteria, taking into account the interests and needs of developing States, particularly the least developed and the land-locked among them” (UNCLOS, Article 82 (4)).

22. The relationship that the majority finds between Article 82 and the principle of the common heritage of humankind is not shared by the International Seabed Authority in its Technical Study No. 4, which concluded that

Thus, the purpose of Article 82, which is to ensure the equitable distribution of the payments to States parties to the Convention, taking into account the needs of developing States, is achievable in a situation where the outer continental shelf extends into the 200-nautical-mile EEZ and continental shelf of another State.

23. In light of the foregoing, the majority has failed to establish that, under customary international law, the outer continental shelf of a State may not extend within 200 nautical miles from the baselines of another State; consequently, the Court should have granted Nicaragua's request for maritime delimitation.

(Signed)     Patrick L. ROBINSON.

ANNEX TO THE DISSENTING OPINION OF JUDGE ROBINSON

1. Article 56 of UNCLOS provides:

2. In exercising its rights and performing its duties under this Convention in the exclusive economic zone, the coastal State shall have due regard to the rights and duties of other States and shall act in a manner compatible with the provisions of this Convention.

3. The rights set out in this article with respect to the sea-bed and subsoil shall be exercised in accordance with Part VI.”

2. Article 76 of UNCLOS provides:

2. The continental shelf of a coastal State shall not extend beyond the limits provided for in paragraphs 4 to 6.

3. The continental margin comprises the submerged prolongation of the land mass of the coastal State, and consists of the sea-bed and subsoil of the shelf, the slope and the rise. It does not include the deep ocean floor with its oceanic ridges or the subsoil thereof.

4.

1. (a) For the purposes of this Convention, the coastal State shall establish the outer edge of the continental margin wherever the margin extends beyond 200 nautical miles from the baselines from which the breadth of the territorial sea is measured, by either:

   1. (i) a line delineated in accordance with paragraph 7 by reference to the outermost fixed points at each of which the thickness of sedimentary rocks is at least 1 per cent of the shortest distance from such point to the foot of the continental slope; or

   2. (ii) a line delineated in accordance with paragraph 7 by reference to fixed points not more than 60 nautical miles from the foot of the continental slope.

2. (b) In the absence of evidence to the contrary, the foot of the continental slope shall be determined as the point of maximum change in the gradient at its base.

5. The fixed points comprising the line of the outer limits of the continental shelf on the sea-bed, drawn in accordance with paragraph 4 (a) (i) and (ii), either shall not exceed 350 nautical miles from the baselines from which the breadth of the territorial sea is measured or shall not exceed 100 nautical miles from the 2,500 metre isobath, which is a line connecting the depth of 2,500 metres.

6. Notwithstanding the provisions of paragraph 5, on submarine ridges, the outer limit of the continental shelf shall not exceed 350 nautical miles from the baselines from which the breadth of the territorial sea is measured. This paragraph does not apply to submarine elevations that are natural components of the continental margin, such as its plateaux, rises, caps, banks and spurs.

7. The coastal State shall delineate the outer limits of its continental shelf, where that shelf extends beyond 200 nautical miles from the baselines from which the breadth of the territorial sea is measured, by straight lines not exceeding 60 nautical miles in length, connecting fixed points, defined by co-ordinates of latitude and longitude.

8. Information on the limits of the continental shelf beyond 200 nautical miles from the baselines from which the breadth of the territorial sea is measured shall be submitted by the coastal State to the Commission on the Limits of the Continental Shelf set up under Annex II on the basis of equitable geographical representation. The Commission shall make recommendations to coastal States on matters related to the establishment of the outer limits of their continental shelf. The limits of the shelf established by a coastal State on the basis of these recommendations shall be final and binding.

9. The coastal State shall deposit with the Secretary-General of the United Nations charts and relevant information, including geodetic data, permanently describing the outer limits of its continental shelf. The Secretary-General shall give due publicity thereto.

10. The provisions of this article are without prejudice to the question of delimitation of the continental shelf between States with opposite or adjacent coasts.”

3. Article 77 of UNCLOS provides:

2. The rights referred to in paragraph 1 are exclusive in the sense that if the coastal State does not explore the continental shelf or exploit its natural resources, no one may undertake these activities without the express consent of the coastal State.

3. The rights of the coastal State over the continental shelf do not depend on occupation, effective or notional, or on any express proclamation.

4. The natural resources referred to in this Part consist of the mineral and other non-living resources of the sea-bed and subsoil together with living organisms belonging to sedentary species, that is to say, organisms which, at the harvestable stage, either are immobile on or under the sea-bed or are unable to move except in constant physical contact with the sea-bed or the subsoil.”

I. Nicaragua's third submission

2. The Court interprets Nicaragua's third submission “as seeking a specific finding regarding the effect, if any, that the maritime entitlements of Serranilla [and] Bajo Nuevo . . . would have on any maritime delimitation between the Parties” (Judgment, para. 97). Reiterating that a State's extended continental shelf cannot overlap with the area of continental shelf within 200 nautical miles from the baselines of another State, the Court points out that there is “no area of overlapping entitlement . . . to be delimited”, regardless of whether Serranilla and Bajo Nuevo are entitled to a maritime zone of 200 nautical miles (Judgment, para. 99). On that basis, the Court “considers that it does not need to determine the scope of the entitlements of Serranilla and Bajo Nuevo in order to settle the dispute submitted by Nicaragua in its Application” (Judgment, para. 100).

3. It is true that, regardless of whether Serranilla and Bajo Nuevo generate a maritime zone of 200 nautical miles, their entitlements cannot, pursuant to the Court's decisions on the first and the second submissions, overlap with any possible entitlement to an extended continental shelf generated by Nicaragua's mainland coast. However, “the dispute submitted by Nicaragua in its Application” is not limited to requesting a delimitation of overlapping entitlements.

4. In its Application, Nicaragua requested the Court “to adjudge and declare . . . [t]he precise course of the maritime boundary between Nicaragua and Colombia in the areas of the continental shelf which appertain to each of them”Footnote ¹. In its Memorial and its Reply, Nicaragua specified this request, asking the Court to declare that “Serranilla and Bajo Nuevo are enclaved and granted a territorial sea of twelve nautical miles”Footnote ². Thus, by requesting the Court to determine the “precise course of the maritime boundary”, Nicaragua asks about the effect, if any, that the maritime entitlements of Serranilla and Bajo Nuevo would have on the course of the relevant part of the maritime boundary. However, the Court does not respond to this request and leaves the Parties in the dark about the “precise course” of the maritime boundary. Contrary to its statement in paragraph 100 of the Judgment, the Court does not “settle the dispute submitted by Nicaragua in its Application”.

5. The pleadings of the Parties confirm that the delimitation of overlapping entitlements does not exhaust the subject-matter of the present dispute. Nicaragua specified that the dispute before the Court encompassed the question of the scope of the entitlements of Serranilla and Bajo Nuevo as far as this was necessary for determining “the precise course of the boundary”Footnote ³. Colombia did not contest the Court's jurisdiction to decide on this matter, nor did it argue that Nicaragua's third submission was inadmissible. Rather, Colombia engaged with Nicaragua's arguments in substance and thereby confirmed that the question of the entitlements of Serranilla and Bajo Nuevo formed part of the dispute before the CourtFootnote ⁴. As the Court held in Jurisdictional Immunities of the State (Germany v. Italy: Greece intervening), “[t]he subject-matter of a dispute brought before the Court is delimited by the claims submitted to it by the parties”Footnote ⁵. At no point did the Parties take the position that their dispute was restricted to the delimitation of overlapping entitlements. I do not doubt that the determination whether there are overlapping entitlements is “[a]n essential step” and “the first step in any maritime delimitation” (Judgment, para. 42). But I can see no reason — either procedural or substantive — why this should preclude the Court from adjudicating a dispute concerning the existence of an entitlement when it is necessary to do so to determine “the precise course” of a maritime boundary.

6. Nicaragua claims that it is entitled to an extended continental shelf in the area east of the maritime zones generated by Colombia's islands of San Andrés and Providencia and west of the maritime zones generated by Colombia's mainland coastFootnote ⁶. This claim would be well founded if, first, Serranilla and Bajo Nuevo were merely entitled to a territorial sea of 12 nautical miles; second, Nicaragua proved that a natural prolongation of its landmass exists in the area east of the 200-nautical-mile zones of San Andrés and Providencia; and, third, a State's entitlement to an extended continental shelf could pass through (“leapfrog over” or “tunnel under”) another State's 200-nautical-mile entitlement. Had the Court upheld Nicaragua's claim, the part of the maritime boundary between the two States which is relevant for the third submission would start in the north where the limit of the 200-nautical-mile zone generated by the Colombian islands of San Andrés and Providencia meets the point where the rights of third States might be affected. From there, the boundary would follow the limit of the 200-nautical-mile zones of San Andrés and Providencia to the south, until it intersected the limit of the 200-nautical-mile zone generated by Colombia's mainland coast. It would then continue north-east along the 200-nautical-mile limit of Colombia's mainland coast until it again reached the point where the rights of third States might be affected.

7. Colombia, in turn, maintains that Serranilla and Bajo Nuevo are each entitled to an EEZ with its attendant continental shelfFootnote ⁷ and that any claim of Nicaragua to an extended continental shelf within that area is excludedFootnote ⁸. Had the Court upheld Colombia's claim, the maritime boundary between the two Parties would start, in the north, where the limit of the 200-nautical-mile zone generated by Nicaragua's mainland coast meets the point where rights of third States might be affected, and would run south until it intersected the starting-point of the boundary established by the Court in its 2012 Judgment (see Judgment, p. 16, point A on sketch-map No. 2). It would then follow that boundary until the endpoint (ibid., Point B on sketch-map No. 2), from where it would continue south along the limit of the 200-nautical-mile zone generated by Nicaragua's mainland coast, to the point where the rights of third States might be affected.

8. Ascertaining whether the three conditions mentioned in paragraph 6 above have been fulfilled is thus a precondition for determining the precise course of the maritime boundary between Nicaragua and Colombia. This is true even if Nicaragua were only able to prove that the natural prolongation of its land territory covers just a part of the relevant area which it claims — assuming that Serranilla and Bajo Nuevo are enclaved and that a State's entitlement to an extended continental shelf may pass through another State's 200-nautical-mile entitlement. In that case, the maritime boundary would still follow the 200-nautical-mile limit of the zones generated by the coasts of San Andrés and Providencia.

9. For these reasons, I do not think that the Court should have rejected Nicaragua's third submission at this stage of the proceedings. The Court should rather have given the Parties the opportunity to present their case and to argue whether Serranilla and Bajo Nuevo generate a maritime zone of 200 nautical miles, whether Nicaragua can prove that the natural prolongation of its coast actually extends to the area around the territorial sea of Serranilla and Bajo Nuevo (a question which might have required the Court to seek the help of experts or assessors), and whether a State's entitlement to an extended continental shelf can pass through the 200-nautical-mile zone of another State.

10. In particular, the Court should have given the Parties the opportunity to present oral arguments on the latter question. In their written pleadings, the Parties took opposing views on the possibility of “tunnelling” under or “leapfrogging” over a 200-nautical-mile zone, here the 200-nautical-mile zones generated by San Andrés and ProvidenciaFootnote ⁹. The Court could then have clarified whether such “tunnelling” or “leapfrogging” is possible under customary international law. This question was touched upon briefly by an ITLOS Special Chamber in a judgment rendered after the hearings in the present case in December 2022Footnote ¹⁰. However, the judgment of the ITLOS Special Chamber does not relieve this Court of its obligation to hear the Parties on the disputed questions.

11. Had the Court addressed Nicaragua's third submission in a further phase of the proceedings, it might have found itself again faced with the question whether it should declare one or more of the legal questions raised by this submission to be preliminary, to be dealt with in yet another separate phase of the proceedingsFootnote ¹¹.

12. In conclusion, I think that “[o]nce the Court has been regularly seised, the Court must exercise its powers”Footnote ¹². Indeed, the Court “must not exceed the jurisdiction conferred upon it by the Parties, but it must also exercise that jurisdiction to its full extent”Footnote ¹³. Otherwise, the Court is adjudicating infra petita.

II. Nicaragua's first and second submissions

13. I doubt that UNCLOS can be interpreted as originally implying a rule according to which the extended continental shelf of one State may not extend within the 200-nautical-mile zone of another. I also doubt that such a rule was part of the original crystallization of the customary international law régimes governing the exclusive economic zone and the continental shelf. However, I have come to the conclusion that such a rule has subsequently emerged as a rule of customary international law. This is why I find paragraph 77 of the present Judgment to be particularly important. The fact that the Court, in its reasoning, has not described and evaluated the relevant practice and the accompanying attitudes of States in more detail does not mean that its Judgment rests on a mere assertion.

(Signed)   Georg NOLTE.

I. INTRODUCTION

1. This opinion explains why I have voted against all subparagraphs of the operative clause of today's Judgment. The questions that the Court had set out to address in the present phase of the proceedings were cast in abstract terms, detached from the specific facts of the case before the Court (see paragraph 14 of the Judgment). This was the reason I supported the Order of 4 October 2022. In my view, however, the Court's reasoning allows considerations specific to this case to colour its discussion of abstract principles.

II. THE FIRST QUESTION

2. The first question was worded as follows:

III. CONCLUSION

37. For the reasons set out above, I think that the Court is not in a position today to reject the submissions that Nicaragua made in its written pleadings. In my view, the Court should have responded to both questions formulated in the Order of 4 October 2022, and it should have proceeded to hold oral proceedings to decide the remaining issues dividing the Parties in this case. In voting against the rejection of Nicaragua's proposed delimitation lines, I do not necessarily endorse Nicaragua's position on the question of maritime delimitation. Rather, I express my reservations about the Court's rejection of Nicaragua's position on the question of maritime delimitation without the benefit of oral argument.

38. My reservations remain regardless of the Court's answer to the first question. As the term suggests, and as Article 60, paragraph 2, of the Rules indicates, a party's final submissions are its final word in a case. By contrast, each party is free to amend the submissions it presents in its written pleadings, provided that it remains within the confines of the dispute as presented in the applicationFootnote ⁵⁴. At the end of its oral argument in the present phase of the proceedings in this case, Nicaragua formally reserved its right to complete its final submissionsFootnote ⁵⁵.

39. The Judgment shifts its focus from the final submissions presented by Nicaragua at the oral proceedings to the submissions that it had presented in its written pleadings. Those written submissions were formulated at a time before the Court's decision to direct the Parties to specific questions, and they address issues extending beyond the Court's focus at the current stage of the proceedings. This fact in itself justifies allowing the Parties to revise their positions on these issues in light of today's Judgment.

(Signed)    Hilary CHARLESWORTH.

Procedural issues

1. The range of procedural deficiencies and abnormalities in and of itself calls into question the credibility of any substantive findings of the Court, whatever they might be.

2. The Court does not deal with the present case as envisioned in its Statute (see Article 38, paragraph 1; Article 43, paragraphs 1 and 5; and Article 54, paragraph 1) and its Rules (see Article 31; Article 49, paragraph 4; Article 58, paragraph 1; Article 60, paragraph 1; and Article 61).

3. Article 43, paragraph 1, of the Statute provides that “[t]he procedure shall consist of two parts: written and oral”. In contrast, the oral proceedings in this case have been restricted to the discussion of two questions of pure law formulated by the Court.

4. Indeed, Article 61, paragraph 1, of the Rules indicates the approach that the Court ought to take where there are particular issues “it would like the parties specially to address” or when “it considers that there has been sufficient argument” on certain points. However, such possibilities stand in contrast to the present case, where the Court ordered the Parties to “exclusively” consider certain questions (Judgment, para. 14) without allowing for argument on any other points, including Nicaragua's second and third submissions.

5. Thus, the Parties were deprived of the opportunity to complete their respective presentations of the case, which is inconsistent with Article 54, paragraph 1, of the Statute. This is made even clearer in the French text, which provides for the presentation by agents, counsel, and advocates of “tous les moyens qu'ils jugent utiles”.

6. The incompatibility between the absence of full oral proceedings and the Statute of the Court is further reflected in Article 43, paragraph 5, which requires the proceedings to include the hearing of experts, whom the Parties had engaged in this case but who were left unable to present their positions to the Court (see also Article 58, paragraph 1, of the Rules of Court).

7. Despite Article 60 of the Rules of Court, the Parties were not permitted to make oral statements to cover “what is requisite for the adequate presentation of that party's contentions”. Indeed, the arguments did not cover all the issues that still divide the Parties. Instead, they were required to repeat arguments that had been prepared in written proceedings and in oral proceedings in an earlier case between them.

8. No final submissions relating to the substance of the case, which in accordance with Article 60, paragraph 2, of the Rules of Court ought to be presented at the end of the oral phase, were allowed. Yet, the Court rules on these issues in the operative clause (Judgment, para. 104), including the issue manifestly unrelated to the questions of pure law formulated by the Court (ibid., para. 104 (3)). The only oral submissions at the end of the hearings made by Nicaragua concerned these two questions and the “fix[ing of] a timetable to hear and decide upon all of the outstanding request in Nicaragua's pleadings”. This latter submission was rejected by the Court.

9. The source of all the irregularities mentioned above is the Court's unprecedented Order of 4 October 2022, which was adopted in departure from Article 31 of the Rules of the Court without consultation of the Parties (see the joint declaration of Judges Tomka, Xue, Robinson, Nolte and Judge ad hoc Skotnikov).

Substantive issues

10. The position taken by the Court in its Judgment of 19 November 2012 in.the Territorial and Maritime Dispute (Nicaragua v. Colombia) case (hereinafter the “2012 Judgment”) and in the Judgment of 17 March 2016 on preliminary objections in the present case (hereinafter the “2016 Judgment”), when read together, leaves no doubt that the Court was ready to consider delimitation once Nicaragua had made full submissions to the Commission on the Limits to the Continental Shelf (hereinafter “CLCS”); all other issues raised by the Parties would have been dealt with in the course of the delimitation process.

11. In its 2016 Judgment, the Court clarified the content and scope of subparagraph 3 of the operative clause of the 2012 Judgment, taking into account the differing views expressed by the Parties on the subject:

That was the only condition set forth by the Court for proceeding to delimitation. Incidentally, such delimitation would not necessarily affect Colombia's 200-nautical-mile continental shelf entitlement (see paragraph 19 below).

12. In its Judgment of 25 July 1974 in.the Fisheries Jurisdiction (United Kingdom v. Iceland) case, the Court made it clear that,

13. The Court's approach in the 2012 and 2016 Judgments was consistent with that dictum, which cannot be said of its Order of 4 October 2022 and the present Judgment.

14. The discussion of the questions of pure law formulated by the Court shows that there is nothing in the United Nations Convention on the Law of the Sea (hereinafter “UNCLOS”), its travaux préparatoires or the circumstances surrounding its conclusion specifically dealing with the possibility or impossibility of delimitation between one State's extended continental shelf and the 200-nautical-mile continental shelf of another State. The Court's finding of a “suggest[ion] that the States participating in the negotiations assumed” a certain position concerning the extended continental shelf based on certain UNCLOS provisions (Judgment, para. 76) seems a tenuous basis for a legal determination, to say the least. The same is true about the characterization of UNCLOS as a “package deal” (ibid., para. 48). There is nothing in this “package” relating to the question to which the Court tries to find an answer. Accordingly, there is nothing therein that could support the Court's conclusion on this matter.

15. The Court seems to rely on the importance of the role of the CLCS in the protection of the common heritage of mankind (Judgment, para. 76). However, that is not the sole mission of the CLCS (see paragraph 11 above). Relatedly, payments and contributions in respect of the exploitation of the extended continental shelf are irrelevant in the present case. Curiously, the Court here focuses its reasoning on the provisions of UNCLOS, which are manifestly not part of the applicable law in the present case, i.e. customary international law.

16. To support its conclusion, the Court refers to the submissions to the CLCS of States parties to UNCLOS (Judgment, para. 77). However, States, in their CLCS submissions, do not consistently refrain from extending a claim within 200 nautical miles from the baselines of another State. Even when they do, this practice is generally unaccompanied by opinio juris, which cannot be simply inferred from practice. In contrast to what the Court suggests in the present case, “[t]he frequency . . . of the acts is not in itself enough” for the identification of opinio juris (North Sea Continental Shelf (Federal Republic of Germany/Denmark; Federal Republic of Germany/Netherlands), Judgment, I.C.J. Reports 1969, p. 44, para. 77; see also International Law Commission, Draft conclusions on identification of customary international law, UN doc A/73/10, p. 129 (Conclusion 3, comment 7)). The Court does not have “authority to ascribe to States legal views which they do not themselves advance” (Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States of America), Merits, Judgment, I.C.J. Reports 1986, p. 109, para. 207). Indeed, for those submissions which do refrain from extending within 200 nautical miles from the baselines of another State, there are other, more plausible motivations, perhaps most notably the desire to avoid a dispute, since a dispute would preclude the CLCS from making recommendationsFootnote ³. In any event, it must be recalled that these submissions are made by States parties to UNCLOS within the specific treaty régime.

17. The existing jurisprudence does not support the Court's conclusions either: in its 2021 Judgment in the Maritime Delimitation in the Indian Ocean (Somalia v. Kenya) case, the Court referred to a “possible grey area” (Judgment, I.C.J. Reports 2021, p. 277, para. 197), while ITLOS and an arbitral tribunal have both accepted the existence of such “grey areas” (Bay of Bengal Maritime Boundary Arbitration between Bangladesh and India, Award of 7 July 2014, United Nations, Reports of International Arbitral Awards (RIAA), Vol. XXXII, p. 147, para. 498; Delimitation of the Maritime Boundary in the Bay of Bengal (Bangladesh/Myanmar), Judgment, ITLOS Reports 2012, p. 119, para. 463). More recently, in Mauritius/Maldives, the ITLOS Special Chamber did not question the possibility of a grey area (Delimitation of the Maritime Boundary in the Indian Ocean (Mauritius/Maldives), Judgment, 28 April 2023, para. 275). The Court itself, ITLOS, and an UNCLOS Annex VII tribunal have thus all accepted the possibility of different jurisdictions dealing with the sea-bed and subsoil, on the one hand, and the water column, on the other. Moreover, another arbitral tribunal has held that there is neither priority nor hierarchy between the rule of distance and the rule of natural prolongation as regards an entitlement to a continental shelf (Delimitation of the Maritime Boundary between Guinea and Guinea Bissau, Decision of 14 February 1985, RIAA, Vol. XIX, p. 191, para. 116). Even more importantly, the present Judgment directly contradicts the 2012 and 2016 Judgments.

18. Hence, the Court's finding that a State's entitlement to a continental shelf throughout the natural prolongation of its land territory to the outer edge of the continental margin may not extend within 200 nautical miles from the baselines of another State is not in accordance with existing rules of international law. In its attempt to legislate instead of interpreting and applying the existing law, the Court has disregarded its function, as provided in Article 38, paragraph 1, of the Statute. Indeed, it has ignored the fundamental principle, according to which “the Court, as a court of law, cannot render judgment sub specie legis ferendae”Footnote ⁴.

19. The only legally sound conclusion that the Court should have drawn is that both UNCLOS and customary international law provide for an equitable solution as the guiding principle in maritime delimitations, which allows, inter alia, for consideration of delimitation of one State's extended continental shelf and the continental shelf of another State to a distance of 200 nautical miles from the baselines from which the breadth of its territorial sea is measured. The Court should have continued with the case in order to implement this principle.

(Signed) Leonid SKOTNIKOV.