
The only World War II submarine to survive a direct depth charge attack navigated home using a faulty gyro compass and a leaking ballast tank.
A German U-boat that sunk during the war was later salvaged and refitted, then used by Allied investigators to study enemy torpedo failures.
Some submarines vanished not from combat but from mysterious giant-scale methane eruptions beneath the Atlantic seabed destabilizing hulls.
More submarines were lost due to internal sabotage and water in ballast tanks than to enemy depth charges in certain campaigns.

The only World War II submarine to survive a direct depth charge attack navigated home using a faulty gyro compass and a leaking ballast tank.
A German U-boat that sunk during the war was later salvaged and refitted, then used by Allied investigators to study enemy torpedo failures.
Some submarines vanished not from combat but from mysterious giant-scale methane eruptions beneath the Atlantic seabed destabilizing hulls.
More submarines were lost due to internal sabotage and water in ballast tanks than to enemy depth charges in certain campaigns.