I feel your pain. I've complained about this before and no one seemed sympathetic. Something is wrong with the enemy AI. As soon as your torpedos hit the target, the escorts zero in on your exact position. How the eff would they know your position. It's one thing to identify that your were on the port or starboard side of the target, but to know the angle and how far away your are is a major flaw in the AI.
I think TDW has mentioned that one escort always knows your exact position due to the original programming of the game. This is a huge flaw of the game and makes it no fun to play.
Your best bet is to only play during the years before Radar and attack from the surface. At least that way you can "get off the X" as soon as the torpedos are let loose. Being submerged is a death wish. You can't cruise with any sort of speed, less you are heard by the escorts hydrophones, and creeping along slowly is pointless because they know your exact position and their active sonar and depth charges are crazy accurate.
Sorry for the rant, I just want this game to be better. The premise of a u-boat simulator is so promising, but this game falls so short in some specific areas.
