Multibeam data were collected with RV Polarstern along the route of cruise PS128 and data acquisition was continuously monitored during the survey. Multibeam sonar system was Teledyne/Atlas Hydrosweep DS3. SVPs were retrieved from CTD and XBT data from other working groups on board. SVPs were processed with HydrOffice SoundSpeedManager (https://www.hydroffice.org/soundspeed/main) and extended with World Ocean Atlas 13 (https://doi.org/10.7289/v5f769gt). SVP data were applied during acquisition. Multibeam data are unprocessed and may contain outliers and blunders and should not be used for grid calculations and charting projects without further editing. The raw multibeam sonar data in Teledyne/Atlas multibeam processing format (.asd) were recorded with Teledyne/Atlas Parastore software as well as Teledyne Reson format (.s7k) in Teledyne PDS. Raw data files can be processed using software packages like CARIS HIPS/SIPS. For updated vessel configuration files check further details.