Just had a wierd thing happen in vanilla 1.4b. I was west of Britian in heavy seas (15 mph winds) when a Hunty Destroyer passed about 2000 m north of me. I went to PD to avoid him, when all of the sudden a sunk ship marker appears on the nav map right where he should be. Checked the hydrophone and periscope, no sign of him! Could he have capsized due to the waves? I'm almost back to port, I'll see if I get credit for him! No "enemy sunk" message though
edit: Nope, didn't get credit for him. Oh well, it was still a 13,000 ton patrol!