UC-41 was lost on 21 August 1917 after suffering an unexplained internal explosion of one of her mines which forced her to suddenly rise to the surface in the Tay estuary, where she was spotted by British naval trawlers and depth charged, killing all 27 German sailors and possibly seven British prisoners of war as well.
•
The Skipper of Nelson, Thomas Crisp was killed and posthumously awarded the Victoria Cross, while the crew of the Ethel & Millie were taken prisoner and presumably were still aboard when the submarine was sunk.
In May 1917 four vessels, the Saint Mungo, Derrymore, Amber and the Morion, were captured and sunk in Ballyhalbert Bay, by U-boat UC 65 under the command of Otto Steinbrinck, one of the most famous U-boat commanders of World War I.
UC-47 was rammed and depth charged by British patrol boat P-57, under the command of H.C. Birnie, off Flamborough Head on 18 November 1917.
Unable to return to Zeebrugge, the boat was steered to El Ferrol, Spain, where she and her crew were interned for the rest of the war.