There was no recorded wreck at this spot so it was described for the relevant authorities, including the Receiver of your Wreck (RoW). They ended up deemed great boats. Through the war 8 had been sunk, a few surrendered and had been ultimately scrapped, and two have been considered missing. https://u3166484.digiblogbox.com/58828503/the-smart-trick-of-u31-that-nobody-is-discussing