>>64226557
It is a surprisingly on topic boat, after surrendering to the British in 1945 U-995 was transferred to the Norwegian navy in 1948 and served together with U-926 and U-1202, also Type VIIC ships, until 1965.

There is even an existing Type XXI in Hamburg, the U-2540 Wilhelm Bauer. That one was scuttled in 1945, 12 years later the Germans raised it and repurposed it into a training ship and testbed for the 206 class.