This data set was acquired with a Kongsberg model EM120 multibeam sonar system during Nathaniel B. Palmer expedition NBP0408 conducted in 2004 (Chief Scientist: Dr. Stan Jacobs). These data files include Sidescan, Swath Bathymetry, Acoustic Backscatter 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): Collaborative Research: Cross-slope exchanges at the Antarctic Slope Front (ANSLOPE); Cross-Slope Exchanges at the Antarctic Slope Front (AnSlope), Leg 3, and funding was provided by the U.S. National Science Foundation.