Numerous collisions over the years have emphasized the need for rapid and efficient ship-to-ship voice communication systems. Such systems, set up to satisfy the demand for more and better channels through which messages can be sent, should guarantee that both sender and receiver come to share the same thoughts and feelings. ‘It can be said that two expressions have the same meaning if their utterance results in the same change of behaviour.’ Recognizing that voice communication systems cannot be effective until all parties speak and understand the same ‘language’, the Maritime Safety Committee of IMCO has developed the Standard Marine Navigational Vocabulary, a significant landmark in the attempt to achieve the maximum safety to navigation and the most appropriate conduct of ships at sea. This paper will concentrate on the objectives of the Vocabulary and will try to ascertain if such objectives have been achieved. The analysis will emphasize the viewpoint of ‘non-English speaking people’ using English ‘for the interchange of intelligence between individuals of all maritime nations’, and will take linguistic considerations into account.