Shiro Mokuba I

The Shiro Mokuba I ("White Rocking Horse I") is a Waver that Nami obtained in the Skypiea Saga, that was later modified by Franky to be used as part of the Thousand Sunny's Soldier Dock system.

History
Nami's waver was first seen in the Jaya arc, where the Straw Hats discovered it on the fallen ruins of the St. Bliss. It was old, but they decided to keep it.

When they reached Skypiea, Nami showed it to Pagaya, who repaired it, and made it good as new. Pagaya pointed out that this waver, unlike other wavers, used a Jet Dial instead of a Breath Dial, so it is able to go much faster.

It was later seen in the beginning of the Davy Back Fight arc when Nami tried it on the Blue Sea and found that it worked on it. Nami had it on the ship and after that it disappeared until it was recently shown to be in the Thousand Sunny.

When Franky explains the Thousand Sunny's Soldier Dock system at the beginning of the Thriller Bark arc, the waver is shown in its new form. It now has a figurehead resembling a Yagara Bull, and has been named the Shiro Mokuba I ("White Rocking Horse I"). However, Nami severely scolded Franky for remodeling her waver without her permission.

Usage
Nami's waver played it's biggest role in the Skypiea Saga. Nami not only used the waver to get around Sky Island, but the waver also proved instrumental in the fight between Luffy and Enel. Both Nami and Luffy rode the waver on a collapsing Giant Jack and rocketed off toward Enel's ship for Luffy to fight Enel himself.

Although in the original manga, the waver has only been shown being used so far in the Skypiea Saga, the Davy Back Fight arc, and the Thriller Bark arc, it has been used additional times in the anime. In the G8 arc, Nami had to hide her waver in tall grass, so it wouldn't be spotted by the Marines. She later used the waver to retrieve the gold they brought from Skypiea that the Marines took.

The waver was seen again in the Ocean's Dream arc, where Nami, forgetting everything that had happened after she joined the crew, used it to escape the ship and steal their gold.

The Waver was also seen in the seventh One Piece movie.

When improved by Franky, the waver included a horse figurehead and a new wheel affixed on the handlebars, making it capable of covering any terrain other than water, and doubles the speed of it combined with the jet dial.