I am a conservative player. I check the pull down chart looking for the shipping lanes per the year I am operating, I look for traffic that starts to funnel where maybe 2-3 lanes start to merge, and I place my boat there.
I check for the outer limits of air patrol too and mark them on my map with a compass to try to steer clear.
Then I conserve fuel rather than burn it.
When I do get action, that is when I will run flank speed to intercept.
I do go to my assigned zone, but only for 24 hrs, and then I head for my predetermined hunting zone.
The crew eats well, we listen to good music, have farting contests .. and we get our fair share of action.
Again, use that pull down chart! And, use the milch cows to extend sea time!