HMS Thetis has the rare and unwanted honor of a submarine to have twice sunk and killed her crew. She sank during trials in 1939, drowning 99 men, before being raised and renamed. Sunk again during battle in 1943, her entire second crew was also lost.
A tool shop owner paid $100 for a locked abandoned storage unit, only to find the Lotus Esprit submarine prop from The Spy Who Loved Me inside. He sold it to Elon Musk for $825,000.
During World War 2, Allied submarines would lie on beds of pistol shrimp. The snapping sound made by the shrimp was so loud, it stopped the submarines from being picked up on Japanese sonar.
In 1961 Donald Reid built a Flying Submarine. It was demonstrated on 9 June 1964 where it dove to a depth of 6.5 feet (2 m) then flew to an altitude of 33 ft (10 m).
Four submarines from various nations around the world were all lost a few months apart in 1968. None of the losses were ever explained.
There are four sunken nuclear submarines at the bottom of the Atlantic Ocean. One, located near Bermuda, holds sixteen live nuclear warheads.
A Polar bear attacked a US Submarine when it broke through sea ice in 2003.
A man in Denmark built a 40 tonne 60ft long submarine in his spare time.