The Gummi Ship is the main method of transportation between worlds in the Kingdom Hearts series. Several characters, including King Mickey and Sora, as well as groups like the Heartless and the Nobodies, use Gummi Ships to move between Worlds. These ships are made entirely of Gummi Blocks, made of special Gummi material that allows to travel between Worlds. Gummi Ship travel is a slower, but a more reliable alternative to warping by using a Corridor of Darkness.
Gummi Ships are assumed to be constructed of the meteors that fall upon the world as a result of its door being opened, as noted by Xehanort in the Ansem Report. King Mickey was the first to create a Gummi Ship.
 Before Kingdom Hearts
King Mickey used the Gummi Ship to visit Ansem the Wise in Radiant Garden to discover the reason why the worlds were disappearing. Both Ansem and his apprentice, Xehanort, were fascinated by the Gummi technology, and discovered it was possible because the Heartless had destroyed the world barriers.
 Kingdom Hearts
In Kingdom Hearts, Sora, Donald, and Goofy all use the Gummi Ship to sail across the worlds. Using the most open routes possible the trio traverse the universe in hopes of locating the King and Riku. It is in this game that Riku first discovers that a Corridor of Darkness works faster than any ship, but drains one's life force. After sealing the Keyhole of Hollow Bastion, Leon reveals that when the Heartless are extinguished, it will be impossible to traverse worlds anymore because the world barriers will be reconstructed. Sora, although disappointed, knows it will be for the best. It is unknown what happened to the Gummi Ship after the trio landed in the End of the World, but it probably stays in the world until it collapses, and then falls into the void of darkness.
 Kingdom Hearts II
In Kingdom Hearts II in Mysterious Tower, Yen Sid magically retrieves the Gummi Ship and returns it to Sora and company when they arrive at his tower. King Mickey likely uses his Gummi Ship to travel across worlds as well. In Radiant Garden, Uncle Scrooge reveals how the Gummi Ships were made. This time around, the gang have to unlock Gates in order to make it across worlds before Heartless appear there. Once again, it is unknown what happened to the Gummi Ship when the World That Never Was fell apart, but it is likely that it was recovered and used for Mickey to report to Yen Sid about the location of Ventus's heart later on.
 Kingdom Hearts 3D: Dream Drop Distance
Mickey, Donald and Goofy use the Gummi Ship to travel from the Mysterious Tower to Disney Castle to confront Maleficent, and likely use it to return.
 Kingdom Hearts
In the original Kingdom Hearts, Gummi travel was simple: The ship would move forward on its own, and you could control up, down, left and right. The ability to brake was also included, but merely slowed the ship instead of a full stop. Numerous enemy ships would appear, and upon their destruction would leave a Gummi block or a blueprint for that enemy ship.
The meters reflecting a ship's stats in flight would consist of:
In the garage menu, you could create your own ship, with a block limit almost impossible to reach. Blocks could also be turned and colored for use.
 Kingdom Hearts II
While Gummi travel did not appear in Kingdom Hearts: Chain of Memories, it appeared in a very different form in Kingdom Hearts II. Gummi travel went from an aerial-combat style to a rail shooter. Although the system was very different, the concept became more like a mini-game. A path would only have to be traversed once to get to a world, and then that world would become available without the use of Gummi travel. The most notable differences in the system were the ability to turn the ship around during flight, the Medal Point system, the concept of in-flight bosses, and the addition of Teeny Ships (referred to as Tiny Ships in Kingdom Hearts II Final Mix), smaller ships that can fly alongside you.
Once opened and completed, each route has three additional, optional Gummi Missions; these each have set goals, a different score system, and prizes. Blocks and new Gummi Ship abilities can be awarded for high scores, and dropped by rare ships in battle.
Gummi Ship stats were increased to five:
Ship customization was also improved over the first game. Along with coloring blocks, the player also has the choice of using block skins with special designs. New block-types were included, such as blades, shields, saws, propellers, and even wheels; in addition, instead of a "Block Limit", each block has a cost to limit the size and power of the Gummi ship. Finally, an ability system was added, granting certain powers to the ship during flight. Completed blueprints were also awarded for exceptional flight on certain missions, both as useful ships or as Final Fantasy-shaped novelty Gummi ships.
 Other Features
 Ship Modification
Gummi Ships can be modified and customized extensively through the use of additional Gummi Blocks. Many of the most rare and powerful blocks must be won or found through the course of the game. In Kingdom Hearts, Gummi Blocks were frequently rewards from chests, but in Kingdom Hearts II, they can only be won through completing Gummi Missions. In addition, Kingdom Hearts II allowed players to create special "helper ships" called Teeny Ships.
 Gummi Weaponry
Gummi Ships, like most ships in classic space-faring games, use lasers to exterminate enemies. A ship can use anything from small head guns to Energy Cannons on the back of the ship. In the first game, Thunder blasters were used to damage enemies; in addition, weapons named after powerful spells from the Final Fantasy franchise fired lasers with homing capabilities. In Kingdom Hearts II new weapon types were added. Blasters now came in three types - Fire, Blizzard and Gravity, while Thunder Gummis were now lasers. In addition to cannons and lasers similar to those from the first game, a ship could be equipped with two new types, Slash and Impact Gummis. The former fill a special gauge as enemies are defeated, and when full, the Gummi unleashes a powerful, devastating attack. The latter deals damage when enemy ships collide with the player's.