bfd...a diesel is almost undetecable when on battaries and ESPECIALLY in the middle of all the ambient noise generated by task force NOT conducting 100% ASW operations.
I was in the middle of a NATO task force, where we were the bait. Our own Navy couldn’t find us. We sank every ship in the whole flotilla.
Finally they made us go through a 1 mile wide check point so they could sink US!
skimmers = targets
pure and simple.