Usual repair items on a sub:
Not that great at 150 feet. Anyway, I believe you will slowly loose hit points on the sub the longer you stay submerged deep. If your hull is at 66% you are in big trouble. I recommend no more then 100 feet and run like hell. Forget silent running. Your number is up at the moment. Have the men keep repairing and flank speed with lots of twisting and turning. Good Luck!