Graphic representation of radio acoustic ranging navigation (RAR) as used by the Coast and Geodetic Survey

Graphic representation of radio acoustic ranging navigation (RAR) as used by the Coast and Geodetic Survey. With this system, the C&GS surveyed the continental shelf and continental slope of most U.S. waters prior to the World War II with unprecedented accuracy for far offshore surveys. Many discoveries were made including many unknown canyons, seamounts, and Mendocino Escarpment.