The Drumming That Jammed the Navy
In 1942, Navy listening posts guarding Chesapeake Bay against U-boats were drowned out each evening by a loud drumming, like pneumatic drills under the water.
What was reported
During the Second World War, the US Navy placed underwater microphones at the mouth of Chesapeake Bay to listen for German submarines. In spring 1942, operators began hearing a roaring, drumming noise every evening, so loud it drowned out everything else. Some feared it was a new enemy device to jam their listening.
The Navy turned to marine biologists. Among them was Marie Poland Fish, who went on to spend decades recording and cataloguing the sounds of hundreds of kinds of fish.
Explanations offered
The noise came from vast shoals of croakers, fish that make a drumming sound by vibrating muscles against their swim bladders, especially in the breeding season. The discovery showed that the sea is full of animal sounds, and the Navy later used recordings of them to train sonar operators.
- When
- 1942
- Where
- Chesapeake Bay, Virginia, USA
- Witnesses
- US Navy sound operators and Marie Poland Fish
- Status
- Explained
Famous cases are real, widely reported events. Each file sets out what witnesses said and the explanations that have been offered, without taking a side.
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