There was no recorded wreck at this location so it was claimed into the pertinent authorities, including the Receiver from the Wreck (RoW). They ended up regarded as exceptional boats. Throughout the war 8 were being sunk, 3 surrendered and have been ultimately scrapped, and two ended up considered lacking. https://simontrkdv.blog2news.com/34785176/the-best-side-of-u31