Waves of Influence, which is the result of a 2019 Dumbarton Oaks symposium, discusses current knowledge about the Pacific maritime networks connecting northwestern South America, Central America, and Mexico in prehispanic times. It was coedited by Christopher Beekman and the late Colin McEwan, who worked on this book until the month he passed. One of the chapters (Zarrillo and Blake, p. 137) summarizes the purpose of this book as “reexamining past ideas in new ways, [which] prods us to leave no stones unturned (or no pods unopened).”

The chapters elaborate on the old idea in archaeological studies of frequent face-to-face contact among people sailing rafts along the Pacific Coast, which to this day lacks direct material evidence. Early claims of contact via maritime networks along the eastern Pacific Coast were based on written records from the sixteenth to eighteenth centuries and from isolated findings discussed in works from the 1960s (Coe, American Antiquity 27(4):579–580, 1962; Lanning, American Antiquity 29(1):99–101, 1963). A review of another Dumbarton Oaks edited volume, The Sea in the Pre-Columbian World (Benson, 1977) stated, “The sea is being recognized as a source of basic data in American prehistory. . . . The lack of excavated sites and published reports is a constant reminder to the reader of the inconclusive nature of the subject. Yet each paper points to exciting possibilities” (Scott, American Antiquity 44(2):383–384, 1979). Yet, despite the effort made by the authors in this publication, the topic of contact via maritime networks is so complex that the review written in 1979 is still valid.

The book is organized into four parts: (1) deep time and broad brush; (2) early versus late networks along two key coastlines; (3) point-to-point contacts between Ecuador, Costa Rica, and Mexico; and (4) the long reach of Spondylus. Most of the chapters are framed under six broad topics suggested by the editors (pp. 3–28): the contact-era network, geography, maritime technology, the linguistic framework, biological evidence, and modes of interaction and forms of evidence. Some of these topics are more developed than others. Most of the chapters make an extended but necessary account of the social, chronological, and contextual conditions of the research presented, emphasizing the possibilities of contact not as a prime mover but as an additional factor to explain the social dynamics of many prehispanic societies.

The book aims to answer several questions, which are wholly or partially discussed in its chapters. Was trade carried out primarily down the line or by direct contact? How does analyzing artifact similarities between regions advance the knowledge of maritime contacts? Who were the primary vectors of transmission: traders, itinerant artisans, or sailors? And, have we overestimated the importance of trade in material goods as opposed to the exchange of technological or ritual knowledge? A review of the chapters and their broader questions is offered in the discussion section by Joyce. The introduction by Beekman and McEwan (pp. 43–91) is accompanied by a useful appendix in which are carefully compiled all the published references of direct historical sources referring to the maritime trade and exchange along the coast of the Americas. A second appendix lists all the known references to balsa rafts reported in colonial and more recent times in this region.

This book also offers new perspectives positing that the maritime contact was not exclusively between Ecuador and West Mexico but instead involved a myriad of societies located in between that area that actively participated in this sailing network. Data from the coasts of Ecuador, Panama, Costa Rica, Nicaragua, El Salvador, Honduras, Guatemala, and Mexico suggest evidence of possible contacts that in most cases derives from secure archaeological contexts. Each of the chapters is more than final research but also outlines a course for future research, and future discussion on maritime contacts will be driven by the topics raised in this volume. Interesting possibilities include further archaeometry studies on human remains (especially isotopic and aDNA studies), textiles, ceramics, metal artifacts, green minerals, Spondylus shells, and macro- and microbotanical remains. This book already moves from analysis of artifactual collections into arguments based on materials found in scientific excavations. It also goes beyond the classic discussion of maritime contacts to explore ceramics, metal axe monies, and Spondylus shells, thereby addressing textiles, cacao, and the transmission of technology, ideas, and experiences. The chapter written by Zarrillo and Blake offers one of the most convincing cases of the transmission of a tangible resource—in this case a plant—as a proxy for the transmission of a resource that turned out to be more important in the area where it was introduced than its place of origin in South America. The last five chapters on Spondylus shells are very informative and bring up new possibilities of evaluating previous and future models in the procurement and trade of this shell species. This book offers new insights into ethnicity and identity, the historical approach, technological style, social memory, and even modeling annual wind and current variations on sailing raft travel along the Pacific Coast.

What is missing in this book is a more emic perspective. I wish more ethnographic work was included on the coastal communities, whose members are the direct or indirect descendants of the people who experienced maritime trade and exchange in prehispanic times; their narratives are only occasionally mentioned in a few chapters. I was expecting to read more on the sailing knowledge of the fishermen who are still actively working on the coast from Ecuador to West Mexico and who, I am sure, have vital information to share. For example, in Huanchaco, on the north coast of Peru, fishermen tell stories of their parents and grandparents seeing balsa rafts from Guayaquil landing on the beach and trading with them. Members of these maritime communities also share technology about the construction and effectiveness of balsa rafts, sailing boats, and other navigation vessels still in use. This topic needs to be addressed in the future. In this context, the community of practice model explained by Joyce can be used more effectively to understand the social, economic, and politic dynamics of the coastal people involved in maritime trade/contacts in the past.

In sum, Waves of Influence is an exciting and stimulating book that covers many topics related to ancient maritime contacts in prehispanic times. It is also one of the first well-integrated academic books in which the archaeology of South, Central and North America is discussed in equal terms and is well intertwined. It shows the potential to produce significant research when we make an effort to see this continent as a whole and not as the result of nineteenth-century nationalistic divisions, as Joyce wrote at the beginning of her discussion.