Multibeam data were collected during R/V Polarstern cruise ANT-XV/1. Data recording was executed for sonar calibration in Bay of Biscay and sparsely on following transit to Cape Town. Data are unprocessed and may contain outliers and blunders. Therefore the data should not directly be used for grid calculations and charting projects but need to be edited furthermore. The dataset consists of 87 files in ATLAS SURF format which are compressed with GZIP to size of 64.2 MB. SURF data files can be processed using the software packages CARIS HIPS/SIPS or with the open source software package MB-System (http://www.ldeo.columbia.edu/res/pi/MB-System/). The source code for an application programming interface (API) to read and write SURF data is released by the Hydrosweep manufacturer Atlas Hydrographic, Bremen, and published under the GNU GPL. Contact mailto:infobathy@awi.de for data access.