This data set was acquired with a ship-based Echosounder Sonar, Magnetometer, and Gravimeter during Eltanin expedition ELT34 conducted in 1968 (Chief Scientist: Dr. John R. Twiss, Jr.). These data files are of MGD77 format and include Singlebeam Bathymetry, Magnetic Field, and Gravity Field data and were processed after data collection.