Submarine

A submarine, in The Wind Waker, is represented on the gamescreen as a giant floating barrel, approximately 1.4x the length of King of Red Lions. They have a second, barrel-shaped object on the top featuring a doorway. Inside there is a raised section, with a ladder down to a lower section. It is in this lower section that Link must defeat various baddies so that a ladder will drop down allowing him access to a small room in which there is treasure.

Location
Submarines can be found at the following locations:  Northern Fairy Island, C1 Crescent Moon Island, E1 Flight Control Platform, G2 Six-Eye Reef, D4 Bomb Island, F5 Headstone Island, C7 Five-Star Isles, G7 