MBES bathymetry data were collected using the ship's own Kongsberg EM 122 multibeam echosounder during the RV SONNE cruise SO306 CoWIO (Port Louis, Mauritius - Durban, South Africa). The primary goal of the cruise was to search for cold-water coral mounds in the West Indian Ocean. Data were recorded in the EEZs of Mayotte, Tanzania, Mozambique, and South Africa. These studies were endorsed as an UN Ocean Decade 2021-2030 of Ocean Science for Sustainable Development activity. This dataset includes a bathymetric grid produced based on the MBES data collected in the EEZ of Tanzania between 2024-08-17 and 2024-08-27. Postprocessing of raw .all files was performed onboard by Evgenia Bazhenova and Alissa Bach, as well as consequently by Md Mumit Hassan in the frame of his work towards the master thesis at the HCU Hamburg. The QPS Qimera software was used to 1) verify that the SVP data were applied correctly based on the time and location; 2) block outer beams and in-turn data to ensure the best possible quality of the overlapping swaths, 3) routinely clean the point cloud using the slice editor. The final grid was interpolated by applying the average interpolation type and 5 minimum neighbours. Depths measured by the MBES are reported in respect to the water level. Only static draft was taken into account. No tidal corrections were applied during the data acquisition or data postprocessing.

These data should not be used for navigational purposes.