From the Super Mario Wiki
Water Geysers (alternatively Water Spouts or simply Geysers) are pillars of water that rise out of bottomless pits or out of other bodies of water, appearing in New Super Mario Bros. U. They help players across gaps and reach high places. If Mario jumps into one, he will be able to swim until the geyser pushes him to the top by its force. They appear in Above the Cheep Cheep Seas, Urchin Shoals, Waterspout Beach, during the battle with Larry Koopa, and are an integral part in navigating Sparkling Waters. They behave similarly to Sand Spouts, which also appear in the game as well as in New Super Mario Bros. Wii.
Water Geysers reappear as an obstacle on the Mushroom Kingdom U stage in Super Smash Bros. for Wii U, showing up at any point during a match. A Big Urchin can be occasionally seen floating on one of them as a stage hazard.
Fountains of water similar to Water Geysers appear in Super Princess Peach, where its spouting height can be decreased by using the Joy vibe. Also, geysers from the level Gushin' Geysers in Donkey Kong Country Returns 3D are also similar to Water Geysers as they can propel Donkey Kong and Diddy Kong upwards.