The Shark Submerge III is a deep-sea exploring submarine shaped like a shark that can carry three people. It is a part of the Thousand Sunny's Soldier Dock System and can be deployed by the number 3 channel.
The Shark Submerge III is a small three-man submarine shaped like a shark. It was built by Franky in order to aid the Straw Hat Pirates when they ever come across a situation that requires going underwater. The passengers keep in contact with the ship above through a Den Den Mushi. The Shark Submerge III has a diving limit of 5,000 meters. Going below any further than that would cause the sub to crack due to the surrounding water pressure.[2]
Originally in the manga, the Shark Submerge III was first shown to the Straw Hats when Franky explained about the Soldier Dock System in Thriller Bark. While shown, however, it was not until the crew reached the second half of the Red Line that the submarine was seen being used to look for Fishman Island.[3] In the anime, the Shark Submerge III was first shown being used during the Ice Hunter Arc.
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