[CCIP]

My best shot was two separately-aimed torpedoes that hit a tanker from 7200m. It was part of a convoy that I beat up pretty savagely over a couple of days and had got kind of disorganized, with escorts out of sight. It was sailing on the edge of the convoy, with a freighter ahead of it, and no escorts anywhere. I went up on the surface, far enough for them not to see me, used both ships as reference to match their course and speed, and got a decent range reading. I then scooted slightly ahead, got into position to get a dead-on 90 degree shot, and waited for the leading ship to get into a 90 AoB position. I then simply shifted my sights to the 2nd ship (which gave me its exact AoB, because it was following the same course), took a range estimate, fired a fish, took another range estimate, fired another one on it. About 7 minutes later, both of them hit. It was pretty satisfying!

Other than that, I rarely hit anything at more than 2k. Unless they're convoy targets or especially valuable ships (big tankers, big warships), I don't even really try if they're at over 1km.