The last one I paid attention to the depth while sinking collapsed (apparently, since I died) at about 585, going down like a rock from a shore emplacement cannon in FotRSU, holing the torpedo room on the 2nd shot, and the conn on the 3rd... Ole Eagle Eye, with radar (I guess), at about 8500 yards - at night... "Sir! We're under attack!" and less that 2 minutes later, it was over...