Diving on a German Submarine U-89 – Off Ireland Coast August 17, 2019 Unipro2013main Military History, Navy, WW1, WW1 Naval History U-89The German U-boat U89 was on active service during WW1 in the Atlantic Ocean off the coast of Ireland. When on 12th February 1918 she was rammed and sunk by HMS Roxburgh with a loss of all her crew. Depth 60m.