I was a member of the crew of H.M.S. Loch Eck - telegraphist HUFF/DUFF and I remember escorting the u-boat from Kristiansand. I still have a photo of the u-boat in transit. My memory grows dim but as far as I remember we went straight back to Scapa. I don't know what happened to the u-boat after that. I always remember the River Foyle going into Londonderry being full of u-boats. As far as I'm aware they were to be scrapped.
Regards
G.Hassell