Gummi Ship
Gummi Ships are the main way of transportation between worlds in the Kingdom Hearts series. King Mickey, Sora, and the Heartless and Nobodies use Gummi Ship to move about. Apparently, it was invented by King Mickey, and was invested by Uncle Scrooge McDuck. An alternate to Gummi Ship travel is warping via Corridors of Darkness
Pre Kingdom Hearts
King Mickey used the Gummi Ship to visit Ansem the Wise in Radiant Garden to disover the reason why worlds were dissapearing. Both Ansem and his apprentice, Xehanort, were fascinated by Gummi technology, and discovered it was possble because the Heartless had eaten away at the world barriers.
Kingdom Hearts
Sora, Donald, and Goofy all used the Gummi Ship to sail across the worlds. Using the most open routes possible the trio traversed the universe in hopes of locating the King and Riku. It was in this game that Riku first discovered that Corridors of Darkness work faster than any ship, but drain your lifeforce. After sealing the Keyhole to Hollow Bastion, Leon revealed that when the Heartless were extinguished, it would be impossible to traverse world anymore because the world barriers would reopen. Sora, although dissapointed, knew it would 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 stayed in the world until it collapsed, and then fell into the void of darkness.
Kingdom Hearts: Chain of Memories
The Gummi Ship is never mentioned in this game, probably because the three forgot about it, and Riku had no ship to travel on.
Kingdom Hearts 2
In Twilight Town, Yen Sid had magically retrieved the Gummi Ship, and returned it to Sora and company when they arrived at his tower. King Mickey must have used his Gummi Ship to travel accross worlds as well. In Radiant Garden Scrooge reveals how the Gummi Ships were made. This time around, the gang had to bust world barriers in order to make it across worlds before Heartless appeared there. Once again, it is unkown what happened to the Gummi Ship when the World That Never Was fell apart, although it probably fell into the void again. However, King Mickey left a letter, so it is possible that the Gummi Ships were found.
Interior, Exterior, and Weapons
Gummi Ships, like most space faring ships, uses lasers to exterminate enemies. It can use anything from small head guns, to Energy Cannons on the back of the ship. Much like the Keyblade Gummi Ships can be rebuilt to fit certain needs. They range from the size of a shack to the size of a deluxe battleship. They seem to have seats within the front of the ship and one large viewing screen for watching battles.
