Résumé : The need to rethink approaches to underwater archaeology from a community-engaged and heritage co-governance perspective has become a major challenge in the territories of contemporary Maya populations in Central America, particularly in the Guatemalan Highlands. This study presents the process that led to a new archaeological assessment in the waters of Lake Atitlán, where various operations were jointly defined and collaboratively conducted with the Tz’utujil Maya community. We then analyze the outcomes of the initiatives undertaken—both underwater and alongside the archaeological diving activities—which confirmed the existence of an exceptional submerged cultural landscape in Lake Atitlán, shaped by past lake-level fluctuations. Finally, we explore the broader implications of this experience for the development of more inclusive heritage management policies—at both regional and international levels—grounded in the recognition of Indigenous ontologies.