I play version 1.4 for DVD. That is my strategy for a quick single mission. For campaign mode I take my time with them. First, I round their side and aim for fuel/coal bunkers to try and take 'em out as fast as possible. If this fails, I dive right under them and fire a stern torpedo at them. This can only be done on my account of Rudolf Hesse with his VII-C. Quite effect, actually. For convoys, my main tactic is to hit and run. I deploy decoys behind the convoy to confuse the escorts, and then come 'round to the side of the convoy. I fire and hopefully sink my target or I must repeat the process. In some cases I take it right through the middle of the convoy just to satisfy my thrill.