In this game almost all of Mario's items are extensions of a water pack he is given. When Mario gets the Turbo or Rocket nozzle, they only replace the hover nozzle and the regular spray nozzle is always intact. There are certain levels where Shadow Mario steals this machine and Mario must use his own abilities to progress the level.
A water nozzle strapped to Mario's back throughout the entirety of the game, F.L.U.D.D. which stands for Flash Liquidizer Ultra Dousing Device, is used as Mario's central attack in order to repel enemies and cleaning up mud in order to unlock new levels.
Two nozzles on either side of Mario that allow him to hover across large gaps or sometimes just to keep from falling off of a ledge.
Once Mario obtains this feature, he can charge up the water in his pack and reach greater heights and very useful in order to find some hard to reach shines and levels.
When Mario possesses this, it fan blasts water like a jet, which allows him to run/swim much faster and break through certain doors hiding secret coins.
Refills water tank.
Activates and maintains Yoshi and helps gain 1-ups for special missions.