SH3 and its wonders

SOrry for this same old same old topic, but i really need help. I havent found any video tutorials to manually sink a ship. I would love to play this game, but as hardcore simmer i am, everything have to be 100% realism. COUld some one please explain me in babysteps the method to do that? Detection to destruction. I would really be thankful.
Any advices and links are welcome. Even stupid ones..