Rescue buoy (submarine)

A large steel buoy, painted red and white, could be seen in a deck housing on most submarine classes.

Soviet submarines also had two rescue hatches and these were highlighted by white painted rings.

Such automatic sensors proved unreliable and buoys were sometimes released unexpectedly.

Accidental release of a buoy would have been a hazard during wartime operations, or even during exercises.

[1] This may have been a factor in incidents such as the Kursk submarine disaster, where the buoy was not released and it was difficult to locate the wreck.