Among my husband's massive collection of papers was this: a log sheet from German u-boat (submarine) U-776, with what looks to be the last entry made by the German crew before being officially handed over to the Royal Navy in the UK. (But I could be wrong, as I can't read the names. The notations are in pencil.)
U776 had surrendered herself to the British in Weymouth, England in May 1945. She never saw combat, having made only one training cruise. She was moored in front of the Houses of Parliament for some time so that people could view her, and is the only U-boat to have ever sailed up the Thames.
Brief footage of U776 on the Thames is included at this Pathe link
After the war, "Operation Deadlight" took care of disposing of the captured German fleet including over 100 U-boats, among them U776. After their surrender, the majority of these submarines were sunk about 100 miles NW of Ireland, although some were in such poor condition that they couldn't make the full trip and were sunk along the way.
While Operation Deadlight destroyed many of the U boats, some were claimed as war booty/reparations. U-505, which had been captured by the US in 1944 instead of being surrendered, is now on display in Chicago as a war memorial.