And found another two wrecks in addition. Result. "A mystery has been "finally solved" after divers found the resting place of a missing German U-boat. The vessel UC-18 was lost in 1917 after a battle with a secret Royal Navy ship, Lady Olive, which was also sunk. It took a team four years to locate and verify the find in the English Channel, which has been filmed for a BBC documentary. Underwater filmmaker Karl Taylor said he was "elated". The battle between UC-18 and Lady Olive is the only known altercation where a submarine and a Royal Navy ship sank each other. In addition to the resting place of the submarine and its 28 lost crew, the dive team also located what they believe to be Lady Olive." Mystery solved after Guernsey divers find missing German U-boat - BBC News