Maybe not related but I ran into a ghost DD once. Found a small convoy of 2 large passengers and a DD. Took out the DD and moped up the passengers.
Feeling rather good about myself I saved and continued along the course the convoy had approched from. Spotted a warship, dove and approched for VID. It was another DD, dead in the water. At this point I thought it was another escort for the convoy that was bugged somehow. Bieng the cheap bastard that I am I decieded that is no escuse for bieng dead in the water during the war and creeped up for an attack
2 fish away, sweet hits (dead in the water, too easy) she was on fire but other than that no sinking or even moving. My interest is peaked on what the game is doing now so I send a few more fish, no reaction. I speed up TC for 10 mins or so and she dissapears, vanishes without a kill or any indication there was ever a ship there. Reloaded the save and got the same results. Creepy.