I always get busy modding about mid-1941, so my careers rarely last longer than that... that being said, I've arrived at something that's taken me past July, so I think I'm about to! I believe the enemy assumes that you go deep, so I stay shallow :P It's worked so far. I've ended more careers from being on the wrong end of a minefield than from being on the wrong end of an ashcan
I do wish I had a proper radar warning device tho...