These bathymetric data were produced using the interferometric side-scan sonar onboard the Haliotis Research Vessel, Operated by Genavir, for the French Oceanographic Fleet,  in September 2022, during the oceanographic campaign HISOPE (l'Haliotis pour l’Imagerie Sismique d’Orbetello et Pyrgi Etrusques). The investigated area is located in front of the prominent archeological site of Pyrgi,  the etruscan harbor of Cerveteri. At the site, next to the sea, is found a series of etruscan temples, surrounded by an etruscan city largely destroyed by coastal erosion. A roman castrum dating back to the 3rd century BCE covers part of the site and is also partly eroded by the sea. Above the castrum is built a fortified medieval village as well as a large renaissance castle (Santa Severa), built over a submerged lava dome (the Massicciata reef). In 2019, foundations of an etruscan monument were discovered 150 m offhshore, over a larger reef located south of the archeological site (the Secche di Macchiatonda). The goal of this campaign was to map the seafloor along this stretch of eroded coastline, in order to determine the location of the coastline in Etruscan time, such as to better understand the geography of the site when the harbor was settled. One of the main questions is  why this specific site was chosen to develop a port, despite its exposure to waves. Acquisition took place under stormy conditions, such that only 1.5 day of acquisition was possible over the 7 days planned. Geoswath mapping was conducted under heavy swell conditions along the sandy coast, north of of the castle of Santa Severa, then in front of the sandy coast, south of the castle, and finally over the extensive  Secche di Macchiatonda reef in the south. Data were acquired by eng. Quentin Layahe, Genavir, onboard the Haliotis, piloted by Serge Garcia, and post-processed using the software Globe, developed by the IFREMER, by Dr.Gilles Brocard (Archéorient, University of Lyon 2, France) and Alessandro Conforti, research engineer at the CNR (Italian national center for research) at Orosi, Sardinia.