This data set was acquired with a Kongsberg model EM120 multibeam sonar system during Nathaniel B. Palmer expedition NBP0908 conducted in 2009 (Chief Scientist: Dr. Teresa Chereskin). These data files include Sidescan, Acoustic Backscatter, Swath Bathymetry data and were processed at sea using the open source MB-System multibeam sonar processing software. Data were acquired as part of the project(s): Collaborative Research: Dynamics and transport of the Antarctic Circumpolar Current in Drake Passage, and funding was provided by the U.S. National Science Foundation.