Contact with HMS M2 was lost in January 1932 during routine exercise; ... With her protected status as a War Grave, the wreck of HMS M2 has now become popular dive site with recreational scuba divers.

An hour later a passing coaster noticed a large submarine diving stern first. HMS M2 was found on the bottom eight days later. The hangar door was open and the aircraft still in it.

HMS M2 was found with the aircraft hangar door open The submarine sits silently on the seabed. Inside, the bodies of 58 sailors still rest, 80 years after the vessel sank in the English Channel ...

British Royal Navy Submarine HMS Triumph, N18, at sea, date not given. / Getty Images The last attack by the vessel is believed to have been against an Axis cement freighter.