A telemetering hydrophone

This report describes a deep, telemetering hydrophone which transmits its information acoustically through the water to a surface vessel. The instrument has the advantage of requiring no electrical cable to the ship and, being self-contained, may be quickly hung on any suitable supporting line or wire. Alternatively, any type of inexpensive single-conductor cable of sufficient strength, such as oil-well logging cable, may be used to replace the acoustic link for some purposes if desired.