Playing through to the end is the real challenge, It's easy early in the war, why do you think they called it the "Happy times". Remember also that as time goes along good upgrades come online as well. Improved torpedoes, Snorkel, radar detection, just to name a few. If you read up on the improved torpedoes, you can still take on convoys have success and have a good chance of escape. The only change is you now attack from a distance, instead of up close or within a convoy early in the war. That's where the pattern running torpedoes come into play.
Good hunting, stay slient and deady takes on a whole new meaning later in the war.
