Multibeam sonar surveys ensonify the seabed beneath and to either side of the survey vessel. They record continuous and very accurate spot heights for thousands of points on the seabed as the vessel moves forward.

From multibeam data, 3D terrain models are created. Depressions and features that project from the seabed can be displayed and measured accurately.

For this project a Reson SeaBat 8125 multibeam echosounder, provided by NetSurvey Limited, was used and the data was processed by Wessex Archaeology using the IVS Fledermaus visualization system.

The results were 3D terrain models, 3D fly through movies and 2D georeferenced images. The 2D images were used as a base for site plans.