Were there any German submarines sunk after 25th of April 1945? The days just before the fall of Berlin.
More than 20, depending exactly how you count them. U-boat.net has a list of them all.
How to count them is indeed critical.
- A surprising number were taken over by the Japanese after the German surrender. Do they count as German losses?
- U 183 was sunk on April 23th, two days before the date of your question, while running with a German crew and a Japanese flag.
- U 56 was sunk on April 28th, U 286, U 307 and U 1017 were sunk on April 29th, U 879 and U1197 were sunk on April 30th, U 2359 was sunk on May 2nd, U 1210, U 2521 and U 3032 were sunk on May 3rd, U 393, U 711 and U 2338 were sunk on May 4th, U 534 and U 579 were sunk on May 5th, U 853, U 881 and U 3523 were sunk on May 6th (from the German Wikipedia, I might have missed a few).
- An unsurprising number was scuttled after confusing orders from the German naval command. These were sunk, but not by the Allies.