Yea...Imagine if we had to play with a gun to the back of our head and if we lost our sub, BAM.....
wonder if that would change our tactics. Just think how your style of play would change.
That's how I try to play, as if it were the real thing.
He who chickens and runs away,
Lives to chicken another day
If I was actually in that role that I'm playing, my primary objective would be to survive the war. That's sound tactics anyway, you don't win a war by dying for your country, you win by staying alive and making the other SOB die for HIS country.

So you pull out of the harbor, cruise in circles for a couple months and pull back in? Let someone else get all the medals and glory. Won't work, they'll demote you to desk warrior. So compromise, calculated risk, the idea is to be a coward without giving the appearance of being a coward - run away every chance you get when there are destroyers involved (the name alone is frightening, a "destroyer" is called a destroyer because it was specifically designed to destroy submarines, what kind of vessel am I commanding again?

), instead only attack unescorted merchants. Get a sound contact on a convoy or task force that's coming straight at you, get out of the way and let it go by. The only time you actually attack a convoy or task force is if it's your mission objective. Play that way and you will survive the entire war without getting the black marks (chicken feathers) that would end the career with embarrassment instead of death.
Obviously that ain't much fun, so again compromise - attack convoys or task forces when conditions are ideal - for example I had a photo recon of Singapore (200 miles of shallow water are you crazy? Send an airplane in there, them flyboys are always looking for glory) and on the way back to deep water i got a BIG task force heading toward Singapore. I'm in 80 feet of water and it's dark and raining, can't even see the bullnose, fuggedaboudit move over and let them go by, find another one in deeper water on a clear day.
It IS hard to do, fire a spread at max range and miss often enough it gets frustrating, now I want to get close and make sure, in real life I would forget it when the pinging gets loud and fast instead of hanging on for the perfect shot as the destroyer is coming closer and closer.
Auto targeting, for hitting fast moving maneuvering targets the manual targeting actually works better, since I can set speed zero AOB zero, range 1000, torpedo actually goes in the direction I point it so I can use Kentucky windage and the mark 1 eyeball to guesstimate the lead angle. Can't do that with auto targeting on, the ship is turning but the auto targeting aims the fish where it would hit if the target was going straight - misses every time.
Map contact update, what we really need there is some purpose for the guy standing at the plotting table - redesign the map so you have an intermediate mode, the guy running the plot gets more accurate as he gets more experienced. Or only add ships that you mark through the periscope, otherwise it's just a sonar bearing line. Biggest reason I play with map contacts ON is them idiots on the bridge watch, I'm trying to do an end around and they report every "new" contact (they lose it and get it back again they don't have the sense to realize it's the same one they reported 10 minutes ago) but ignore the destroyers suddenly turning toward us at flank speed , not worth mentioning since they already reported the first sighting.
I gave up trying to get that working the way it should, hacked the
\Data\Cfg\GameplaySettings.cfg to change
NoMapUpdateRealismPercentage=0 and added those points to auto targeting.