Also to see a battleship roll over through my scope...
!!!That would be memorable!
Actual visual damage would be cool as well with the ability to ba able to repair at sea.
Ducking into a fog bank and elude the enemy for any length of time while nursing your wounds would be a nice addition.
I'm not talking about bringing the hull damage back to an "undamaged" state but simply improving the health bar would be a plus.
Also the option to release debris would be handy and being able to hide on the bottom would add to the realism as well.