So I'm looking into the fate of U-1055. Here is a shortened version of the story, as I know it:
On the night 5-6th April 1945, MTB 719 and MTB 715 were out on a mission looking for German targets to sink. After a short time, they spot a German U-boat, with escort, heading out to the North Sea(This is in Hjeltefjorden). They begin an attack run, and MTB 715 fires it's torpedoes at the U-boat. I recently got in touch with a veteran who says he saw the torpedoes hit. There was one hit right in the middle of the control tower, and one on either side of the tower. They saw the U-boat sink, and afterwards, oil spillage was sighted in the sea. They returned to base, and claimed to have sunk a U-boat, but were never actually credited with the kill, since German records did not show a missing u-boat for that date. The escorting ship did not actually know the U-boat was being attacked, and figured that the sounds they heard, were of the U-boat letting out air to submerge.
There is one U-boat that fits this story, and that is U-1055: The Type VIIC boat U-1055 - German U-boats of WWII - uboat.net, which left Bergen on the 5th April, and was reported missing 23. April.
However, there are a few things that I still don't quite get.... Let's say the U-boat was attacked, but managed to survive without major damages, would they then have gotten on the radio to report that they had been attacked, or was it normal to keep radio-silence until a certain date, for example if it was supposed to have reported in on the 23. April?
Why was it reported missing on the 23. April?
Now let's say that the U-boat was in fact sunk on the 6th April, and that because of radio-silence protocol, it was not reported until the 23rd?
I am hoping some of you U-boat fans out there might have an answer?