A new type of hydrophone block for Radio Acoustic Ranging.
On the GUIDE
Image ID: theb2247, NOAA's Historic Coast & Geodetic Survey (C&GS) Collection
Location: San Clemente Island area, California
Photo Date: 1925
Credit: C&GS Season's Report Luce 1925
Category: Charting/Navigation/Electronic/Radio-Acoustic Ranging/
• High Resolution Photo Available