Non-invasive underwater research in the ancient port of Ptolemais, Libya. New technologies, new perspectives

Polish archaeological mission of the Faculty of Archaeology of the University of Warsaw led by Dr Piotr Jaworski and underwater reconnaissance led by Artur Brzóska worked in the ancient town of Tolmeitha, Libya, in June 2023. A total of about 5.5 km of coastline was explored, with particular emphasis on the harbour area. By employing a hydroacoustic device the team could create two maps. The first is a bathymetric map showing the depth distribution in the harbour and coastal area of the town. The second is a sonar mosaic that allowed anomalies on the bottom to be observed and tentatively interpreted. Thanks to the courtesy of the Tolmeitha Museum aerial photographs were taken with a drone and later compiled into an orthophotograph. Once all the data were integrated, a plan of the harbour with quays and breakwater was created, enabling reconstruction of the size of the harbour and its key installations.