The Advisory Council on Underwater Archaeology (ACUA), the Society for Historical Archaeology (SHA), and the PAST Foundation are pleased to present the 2023 ACUA Underwater Archaeology Proceedings from the 56th Annual Conference on Historical Archaeology. The ACUA Underwater Archaeology Proceedings present the current research conducted by academics, avocational archaeologists, students, and resource managers. The papers published in this volume were originally presented as talks in organized conference sessions and are edited print versions of the research presented. They cover a broad range of topics related to underwater and nautical archaeology, from discussions of specific ships and shipwrecks around the world, to the results of scientific research and analysis, to broad-based data management tools and the development of training studies. Making information widely accessible is one of the key missions of the ACUA. The annual publication of the ACUA Underwater Archaeology Proceedings provides a timely outlet for professional research, and an opportunity for students and avocationals to share their work with a wide audience.