Submarine

In The Wind Waker, a submarine is represented as a giant floating barrel and is sometimes guarded by Bokoblins on wooden rafts. They have a second, barrel-shaped object on the top featuring a doorway. Inside, there are two raised sections on opposite ends of the submarine, with a ladder leading down to a lower section. Link must defeat various baddies in the lower section so that a ladder will drop down, allowing him access to a small room on the other raised section. This room contains a chest with treasure, which may vary from a Treasure Chart to a Piece of Heart. The submarine near the Flight Control Platform holds the Platform Chart, which allows Link to find the Sea Platforms in the Great Sea.

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