The wreckage of a First World War German submarine has been discovered on the sea bed off the East Anglian coast.
The U-boat, which went missing in 1915, is believed to have hit a mine about 55 miles off Caister on Sea in Norfolk.
The wreckage is on the sea bed in about 100 feet (30 metres) of water. A video taken by divers reveals the sunken vessel being reclaimed by the sea.
It was initially thought that the team had discovered a Dutch military submarine which went missing in June 1940 but divers have subsequently confirmed that the wreck is that of the German-built U-31.
The sub, with more than 30 crew onboard, left for routine patrol from Wilhelmshaven on the North coast of Germany on 13th January 1915. It never returned.
The find was made by a survey team from the energy companies Scottish Power Renewables and Vattenfall who are drawing up detailed plans for the new East Anglia ONE wind farm.
The survey team have been scanning the seabed in the Southern North Sea for more than two years. They have covered an area nearly four times the size of Greater London.
As an official military maritime grave, the wreck of U-31 will remain in its final resting place. The wind farm developers have pledged to ensure that the remains are not disturbed when the new turbines are installed.