Ocean Floor

"Dear Self, I know you'll forget, so I'm leaving you instructions to get to the ocean floor."

- Carben

The Ocean Floor is the underwater section of the Ocean Realm that goes below sea level in Spirit Tracks. It follows the same general shape as the above sea level portion of the Ocean Realm, though its section of the Spirit Tracks is somewhat smaller.

The entrance to the Ocean Temple is located in this undersea portion of the realm, which can only be accessed via a magical portal shaped like a fish head that is accessible when three special Crystal Switches are activated via train whistle. However, these crystal switches must be activated in a certain order, which is revealed to Link in a letter given to him by Carben.

As the Spirit Tracks run down beneath the water's surface, any train and its passengers traveling on them to the Ocean Temple are protected from drowning via magical air bubbles that are formed around the passengers' heads. This is thought to be due to the powers the Spirits of Good infused into the tracks when they were created, thus explaining why train tracks would lead to a normally impossible region for trains to maneuver, underwater. The cannon of a train will, instead of firing canon balls, fire torpedoes instead if set off while on the Ocean Floor. The entrance to the Ocean Temple is guarded by a Dark Train and an Armored Train that both seek to prohibit any from entering the structure. Link comes to this undersea region on a quest to restore the energy flow of the Ocean Temple to the Tower of Spirits.

Trivia
Like the entrance to the Catfish's Maw in Link's Awakening, the Ocean Floor entrance above the surface is shaped like a Giant Catfish.