Digital collections

Graphic representation of radio acoustic ranging navigation (RAR) as used by theCoast and Geodetic Survey. With this system, the C&GS; surveyed thecontinental shelf and continental slope of most U.S. waters prior to the WorldWar II with unprecedented accuracy for far offshore surveys. Many discoverieswere made including many unknown canyons, seamounts, and Mendocino Escarpment. (Image credit: NOAA Historical Image)