Single beam sounding system depth record of obstruction with surveyor's annotations such as LTRA (Line turns right about), LR (Line resumes), 180 T ( course of surveying vessel), etc.
Image ID: cgs01121, NOAA's Historic Coast & Geodetic Survey (C&GS) Collection Credit: Office of Coast Survey, Atlantic Hydrographic Branch • High Resolution Photo Available
Publication of the U.S. Department of Commerce, National Oceanic & Atmospheric Administration (NOAA), NOAA Central Library NOAA Privacy Policy | NOAA Disclaimer Last Updated: September 30, 2009
