Storabrun: I can't agree with you. Attacking on the surface is easier (in Happy Times) than submerged, mainly because your ability to maneuvr and react much faster. But this depends on circumstances, like weather (in my opinion the worse weather the better), convoy state (unsuspecting, alerted) and of course your skills.
Skills and patience, as said before (and before that before too). If you are a type of 'fast player' who likes to go up with TC to 64 or more even when at battle, sure surfaced attack is NOT a good idea. But if you take a time, do it carefully, watch around, stay alerted, act carefully, there is a pretty good chance of huge success. Patience needed.
If one runs towards a convoy surfaced at flank speed playing Geronimo... well, it's one's choice to do so.
Then I'd advise him to attack submerged, as the water will make him a bit slower.
