Oh, I wouldn't worry about the AI. The merchants have gone completely insane, they don't "zig-zag" they "Let's change our speed and heading every second or so!". I expended 5 torpedoes trying to hit the slippery bastard before I got a decent broadside shot.
That was after the one of the DDs detected my periscope, sticking just up above the water, in rough seas at 2,000 meters. The depth charges are still nuclear warheads. The other two destroyers from the convoy quickly joined in on the fun and they created a circling line from which I couldn't escape, and closed the circle slowly, all the while depth charging the crap out of the water in between them. Despite decoys, silent running, and every other trick I tried, I died a horrible death in very short order when a number of their charges went off at 20 meters away.
Here's hoping that's tweaked a little bit in the final patch, or won't be "Silent Hunter 4" anymore, it'll be "Silent Hunted 4".
