This data set was acquired with a ship-based Atlas Hydrosweep DS Multibeam Sonar system during Maurice Ewing expedition EW9309 conducted in 1993 (Chief Scientist: Dr. Jean-Guy Schilling). These data files are of MBSystem Compatible format and include 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): Rock Dredging and Geochemistry of the Mid-Atlantic Ridge from 41 Degrees South to 51 Degrees South, and funding was provided by NSF grant(s): OCE90-11741.