Thanks for replying so quickly

Sorry I didn't specify earlier, but my boat is a VIIB. I have spent the past 40 minutes (now 21:40 in game) creeping along at 12m with a mere 2 meters of clearance from the ocean floor, trying to get past these sunken ships, going to dead stop every time the destroyer is facing me, and then creeping along at 2kts once I am in his baffles.
Hopefully, once I am past these sunken ships, I can surface behind them without being seen ...
By the way, any ideas on how one might exit the area after firing my torpedos? ... would hate to attempt to navigate this channel again once all the destroyers get a little testy over the fact one of their battleships is resting on the bottom ...