I found the single missions to not be a great training ground. Simply because I found myself in a position i would not have approached a convoy to begin with. In the campaign if you mess it up you can start again. What works for me especially with a convoy or a task force once I have some intel via radar, sonar or radio. I knuckle around the convoy well past the radar ranges of the escorts. Place my boat in a good intercept position and I get under a thermal layer at all stop and go quiet. I let the escorts pass then it is up to PD and pick a nice juicy merchant. Sneaking past escorts is doable but there are some tricks to it and like a magician we cant give them all away, but you have one good startegy here I gave you to start. Part of the fun is learning by trial and error.
