This data set was acquired with a Kongsberg model EM120 multibeam sonar system during Nathaniel B. Palmer expedition NBP0302 conducted in 2003 (Chief Scientist: Dr. Arnold Gordon). These data files include Acoustic Backscatter, Sidescan, Swath Bathymetry data and were processed at sea using the open source MB-System multibeam sonar processing software. These data are included in the GMRT Synthesis, beginning with version 1. Data were acquired as part of the project(s): Cross-Slope Exchanges at the Antarctic Slope Front (AnSlope), Leg 1, and funding was provided by the U.S. National Science Foundation.