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.