Pole, line, and pelorus for observing direction and rate of current after deploying from anchored launch.
Image ID: cgs01611, NOAA's Historic Coast & Geodetic Survey (C&GS) Collection Photo Date: 1915 circa • High Resolution Photo Available
Publication of the U.S. Department of Commerce, National Oceanic & Atmospheric Adminstration (NOAA), NOAA Central Library NOAA Privacy Policy | NOAA Disclaimer Last Updated: April 30, 2013