Divers from Devonport Naval Base have helped solve a 100-year-old mystery and identified a First World War German U-boat sunk off the Lizard peninsula in Cornwall.
Settling a debate between historians, the group dived 70 metres down into the Channel to positively ID the wreckage of a U-95, by comparing the information on its propellor with official records.
Knowing that all other U-boats of the U-93 to U-98 type either surrendered at the end of World War One or can be easily located, meant experts could narrow down the shipwreck's identity to two craft.
Official Royal Navy records suggested the boat was U-93, a vessel rammed and sunk in January 1918 by merchant ship SS Braenelli.
That U-boat, however, went on to sink two ships and was assigned to operate off Brittany, creating a lingering mystery for historians.
Meanwhile, another near-identical wreck was found off Hardelot on the Pas-de-Calais and estimated by some experts to be the boat's sister U-95.
Using the dive boat Moonshadow, the team of divers overcame the challenge of the wreck's depth and the interference of strong currents.
With dates and new information, they were able to confirm that the Lizard wreck is U-95 and the Hardelot one U-93.
Ramming may still have been the cause of the U-95's sinking, but photographs and video from the dives are still being analysed to make sure, given the presence of a deep minefield not far from where it was sunk.
Among the divers were Dr Fran Hockley and retired Army Air Corps Lieutenant Colonel Dom Robinson, civil servants employed at the Joint Service Sub Aqua Diving Centre in Devonport Dockyard.
Dom Robinson outlined the findings of the dive, saying: "Although there is damage to the port side it wasn't particularly conclusive but we did find open hatches in the conning tower and engine room.
"We think this confirms that it was sunk by ramming which destroyed the submarine's buoyancy system while concurrently pushing it under.
"Bitterly cold January seawater flooding into the open hatches must have been unimaginably horrendous for the crew and even those who managed to escape wouldn't have lasted long in the water," he added.
Cover image: Diver swimming around the wreckage of the U-boat (Picture: Royal Navy).