Early hydrophones could provide a direction rather than a dependable distance, and their bearing could be broad or narrow depending on the equipment and conditions. They did not deliver radar-like precision. A useful bearing nevertheless helped destroyer crews focus a search and organize an attack in darkness. Repeated exercises and an aggressive doctrine turned limited acoustic information into a practical tactical aid rather than expecting the sensor to solve the engagement by itself.
Notable Point · 1:42:06-1:44:28
Hydrophones gave destroyers a bearing in the dark
Acoustic equipment did not supply radar-like precision, but it could point destroyers toward a target and sharpen a night attack.