I was less fortunate yesterday... The convoy I attacked was IJN alright, but I was using my slightly modified cuties (essentially acoustic homing Mk 16's). Sunk the first three destroyers, although I made a hasty shot and missed with one. After a couple minutes I went full battle stations blew the ballasts and cranked up to full power, and started pounding the freighters with the deck guns. Next thing I know I'm knocked all the way down into the control room 'Torpedo Impact, Sir' 'Hull damaged, Sir!' 'We have flooding, Sir!', stern torpedo room is flooding, engine rooms are flooding, 55 percent hull damage. I climb back up on top to find a gaping hole in my stern.
Even worse, I had not saved after the previous convoy attack