Multibeam data were collected during R/V Polarstern cruise ANT-XXII/1. Data recording was executed in Atlantic Ocean from Ampère Seamount to Cape Town for calibration of sonar system Hydrosweep DS2 in HDBE mode. Data are unprocessed and may contain outliers and blunders. For that reasons the data should not be used for high quality grid calculations and charting projects. One file contains a measurement period not exceeding eight hours. The dataset consists of 50 files in ATLAS SURF format which are compressed with GZIP to size of 415 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.