Sea Train

A Sea Train is an anachronistic locomotor in Eiichiro Oda's manga, One Piece. To date, there are only two in existence, both built by Tom the Merman, a reputed and legendary ship-builder from the city of Water 7.

22 years prior to the manga's current date, Tom was considering building a proper Sea Train when he was approached by representatives of the World Government, who sought the merman for the crime of building Gol D. Roger's pirate ship, the Oro Jackson. At the time, Water 7's remoteness and proximity to a large number of Sea Monsters made the port city undesireable for trade, slowly eroding the city and all who lived there. By building his "steam paddle boat", Tom would effectively save Water 7 by opening it up for trade, as well as saving his own life. The Judge overseeing Tom's trial agreed to postpone Tom's crimes for 10 years; if he was successful at building the Sea Train Network, he would be pardoned for his original crime.

When Tom began construction of Water 7's Sea Train Network, he had already built a prototypical steam engine called the Rocket Man. After drawing up a new blue print. Tom's polished train, The Puffing Tom, was originally only connected to Enies Lobby, but Tom took an additional four years to buid tracks to three other nearby islands: Saint Popla, Pucchi, and San Faldo.

By design, a Sea Train is roughly immune to changes in weather; the train's momentum and speed allow it to pulse foreward in any situation, even against an Agua Laguna. Whenever the train passes over the track, a device near the wheels makes an underwater dissonace that drives away Sea Kings. The tracks of a Sea Train lie just under the surface of the ocean, and sway with the tides to avoid resistance damage. The tracks are never repaired, as they are never really "used"; a Sea Train paddles on an ocean's surface, and only needs a track to serve as a guide to its destination.

As of yet in the manga, two Sea Trains have been revealed:

The Puffing Tom, Tom's finest and most powerful Sea Train. Puffing Tom was build during Tom's original ten year hiatus from government persecution, with signficant improvements added over the Rocket Man. Puffing Tom's design was based on historical 19th century steam locomotives.

The Rocket Man, Tom's first attempt at a Sea Train. Rocket Man was designed before Tom's agreement with the World Government. Rocket Man was considered by all who worked on it as an experimental failure; the train could only travel at dangerously high speeds, had no means of breaking, and lacked the momentum to plow though obstacles without getting derailed. The Rocket Man was destroyed after crashing into the isle of Enies Lobby.