The series takes place on the Millhouse island of Illoka. The islanders survive without the use of modern technology, because bamboo and grass doesn't generate electricity, building huts out of bamboo and fern and eating various fruits found on the island floor. Beneath the surrounding ocean lies Quetso, a sunken Millhouse island now home to many sea creatures. Quetso is now ruled by Flipper's parents. During season 3, Flipper and Lopaka discover that Quetso was sunk long ago when King Dextorian brought Neptune's Statue and Trident to the surface. At the same time a sea volcano was set off, sinking Quetso and forming Illoka. The curse of Neptune's Trident is still unleashed on Quetso, and Flipper and Lopaka have to sink the Statue to save everyone
