RT journal article T1 Comparison between the employ of a multibeam echosounder on an unmanned surface vehicle and the traditional photo-grammetric as techniques for documentation and monitoring of shallow-water cultural heritage sites: A case of study in the Bay of Algeciras A1 Solana Rubio, Soledad Estrella A1 Salas Romero, Alberto A1 Cerezo Andreo, Felipe A1 González Gallero, Raúl A1 Rengel, Juan A1 Rioja, Luis A1 Callejo Gómez, Joaquín A1 Bethencourt Núñez, Manuel A2 Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica A2 HistoriaGeografía y Filosofía K1 underwater cultural heritage K1 shallow waters K1 unmanned surface vehicles K1 multibeam echosounder K1 photogrammetry AB Over the last few years, due to various climatic, anthropogenic, and environmental factors, a large amount of submerged heritage has been unearthed and exposed to deterioration processes in the Bay of Algeciras. These impacts can be more severe in shallow waters, where the cultural heritage is more vulnerable to natural and human-induced impacts. This makes it urgent to document cultural heritage at risk of disappearing using different techniques whose efficiencies in the archaeological record need to be determined and compared. For this purpose, we have documented a shipwreck in the Bay of Algeciras using two techniques: photogrammetry and a multibeam echosounder. The photogrammetric method consists of obtaining a 3D model from numerous photographs taken of an object or a site. The processing software creates three-dimensional points from two-dimensional points found in the photographs that are equivalent to each other. Multibeam echosounders are capable of providing side scan imagery information in addition to generating contour maps and 3D perspectives of the surveyed area and can be installed in an unmanned surface vehicle. As a result, we have obtained two 3D visualisations of the shipwreck, i.e., digital copies, that are being used both for the analysis of its naval architecture and for its dissemination. Through the comparison of the two techniques, we have concluded that while a multibeam echosounder provides a detailed digital terrain model of the seabed, photogrammetry performed by divers gives the highest resolution data on objects and structures. In conclusion, our results demonstrate the benefits of this combined approach for accurately documenting and monitoring shipwrecks in shallow waters, providing valuable information for conservation and management efforts. PB MDPI SN 2077-1312 YR 2023 FD 2023-06-30 LK http://hdl.handle.net/10498/29855 UL http://hdl.handle.net/10498/29855 LA eng NO This research was funded by: (1) Ministry of Science and Innovation, Spain, through the project “Vulnerability of littoral cultural heritage to environmental agents: impact of climate change (VOLICHE)” (PID2020-117812RB-I00/AEI /10.13039/501100011033): (2) European Regional Development Fund (FEDER), EU, Interreg V-A Spain-Portugal program (POCTEP) 2014–2020, through the project “KTTSeaDrones” (0622-KTTSEADRONES-5-E). (3) 2014–2020 ERDF Operational Programme and the Department of Economy, Knowledge, Business and University of the Regional Government of Andalusia, Spain, through the project “Between the Pillars of Hercules, underwater archaeology of a privileged space. The Bay of Algeciras (HERAKLES)”. (FEDER-UCA18-107327) DS Repositorio Institucional de la Universidad de Cádiz RD 10-may-2026