The RV Polarstern expedition ANTARKTIS-XXIII/4 (ANT-XXIII/4) began on 10 February 2006 from Punta Arenas returning on 11 April 2006. The main goal of the expedition was to study glaciomarine sedimentation and the evolution of the tectonic-geodynamic setting of the southern Amundsen Sea and Pine Island bay. The objective of the bathymetric working group was to use high-resolution multibeam methods to collect geomorphologic data for locating geologic sampling sites, to interpret magnetic and gravity data, and to contribute to the database of oceanic mapping information of the Southern Ocean. (mte)