Yeah i don't find battleships a lot , only have been able to sink one !
A revenge clas which was surrounded by 8 escorts :p
I can assure u the moment 2 of my 4 torpedo's hit that vessel they all went down to hunt me
Then after heavy damage i lost trail of escorts and battleship but i knew it was heavily damaged en went on with searching, after a day i found him back completely unescorted because he couldn't keep a steady course anymore.
3 more torpedo's finished the job
Another time more in the beginning of the war i saw the hood and 2 other battleships behind it setting sail to the West that was a nice image too
But i've never seen a carrier EVER
