This paper examines the underrepresentation of underwater cultural heritage (UCH) within the United Nations Educational, Scientific and Cultural Organization (UNESCO) 1972 World Heritage Convention. Although the 2001 Convention on the Protection of the Underwater Cultural Heritage provides a dedicated framework, submerged heritage remains inconsistently recognized in World Heritage processes. The paper traces the historical development of UCH recognition, outlines challenges in classification and protection, and considers the potential of sites to be evaluated as possessing Outstanding Universal Value (OUV). It highlights the cultural–natural interconnections of UCH, the risks posed by climate change and human activities, and the need to consider sites in international waters. The authors argue for clearer criteria, interdisciplinary collaboration, and the systematic integration of UCH into nomination dossiers and management plans. This work seeks to inspire stakeholders to prioritize UCH within heritage management systems, ensuring its preservation for future generations and thereby ensuring a balanced representation of human history in the World Heritage List.