This thesis delves into the exploration and documentation of underwater cultural heritage through the application of photogrammetric techniques and Unmanned Aerial Systems (UAS). Focusing on the captivating case study of the Roman Columns of Porto Cesareo (Le), this research encompasses both theoretical and practical dimensions to enhance our understanding of underwater archaeological site surveying and preservation. The initial chapters of this study elucidate the significance of underwater cultural heritage and the transformative role of photogrammetry as a non-invasive, precise method for surveying submerged archaeological sites. Additionally, it delves into the specialized domain of underwater photogrammetry, shedding light on the unique challenges and methodologies involved in capturing accurate data in the aquatic environment.