There are half a dozen Gato or Balao class museum boats around which would have been happy to help with accuracy. The museum boats "docents" would have been very happy to help the director "get it right" and it probably would have been cheaper than using leftovers from Das Boot. If you are going to make a TV movie of an historical event, at least try to get it as accurate as possible.

My two cents, producer and director were just plain lazy and not professional in telling the story as it should have been told. A little more on research, and planning could have saved them $$$ and given us (former submariners) somnething to be proud of.