The Rocket Nozzle is an item in Super Mario Sunshine.
Description
By charging the Rocket Nozzle, Mario can use it to launch straight up into the air, although each charge uses up a small fraction of F.L.U.D.D.'s water. If Mario is launched high enough, he can perform a powerful variation of the Ground Pound to break certain objects.
In Super Mario Sunshine
Mario can find and use a Rocket Nozzle in each main course, although certain episodes do not allow for it. Mario can eventually unlock the Rocket Nozzle in Delfino Plaza to access areas such as the Warp Pipe to Pianta Village, located on top of the Shine Gate.
To unlock the Rocket Nozzle in Delfino Plaza, Mario has to have obtained at least 30 Shine Sprites for Shadow Mario to appear, holding the Rocket Nozzle on the rooftops by the lighthouse. Like the other Shadow Mario encounters, Mario has to run after Shadow Mario and spray him enough times before Shadow Mario quits, therefore dropping the Rocket Nozzle for Mario to use.
The Rocket Nozzle later has an essential role during the final boss battle against Bowser in Corona Mountain.