The U. S. Geological Survey initiated Program EEZ-SCAN in April 1984 in cooperation with the Institute of Oceanographic Sciences (IOS) of the United Kingdom to map the U. S. Exclusive Economic Zone (EEZ) at reconnaissance scale as a first effort to develop a geologic understanding of the new national territory. GLORIA*, a unique side-scan sonar system capable of mapping over 27,000 sq. km per day, is the principal tool being used in the mapping surveys. In 1984, GLORIA surveys were conducted in the EEZ off California, Oregon, and Washington covering an area of approximately 250,000 sq. nautical miles. These surveys were highlighted by discoveries of major geologic features.