This data set was acquired with a ship-based Magnetometer, Echosounder Sonar, and Gravimeter during Eltanin expedition ELT39 conducted in 1969 (Chief Scientist: Dr. Merle R. Dawson). These data files are of MGD77 format and include Gravity Field, Magnetic Field, and Singlebeam Bathymetry data and were processed after data collection.