Rainbow Ship is a special court in the game Mario Hoops 3-on-3. It is the fourth and final court in the Rainbow Tourney, and unlike the other "fourth courts", it is actually played on during the Tourney. The opponents on the Rainbow Ship during the Rainbow Tourney are always the same: Ninja, Black Mage, and White Mage.
The Rainbow Ship court is set on a giant, floating ship high above the clouds. Chocobos (Final Fantasy creatures) adorn the backboards of the hoops and the ship in all just looks very ornate. All of this is just for show, however, as it is a very standard court. This ship debuted in the first Final Fantasy, and it's one of the only three Final Fantasy-based courts in Mario Hoops 3-on-3 (the others being Malboro Garden and Glare Desert).