This data set was acquired with a Kongsberg model EM120 multibeam sonar system during Nathaniel B. Palmer expedition NBP0507 conducted in 2005 (Chief Scientist: Dr. Marcel Croon). 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. Funding was provided by the U.S. National Science Foundation.