Water Rockets are items in the game Super Mario Sunshine. Water Rockets can be found in two missions in Pinna Park. In Episode 1, Mario can pick these up on the Roller Coaster with F.L.U.D.D. They are used in the fight against Mecha Bowser. The mechanical monster will fire Bullet Bills at Mario, which can be destroyed using Water Rockets. Hitting Mecha Bowser himself four times with the Rockets will destroy him.
Later, in Episode 8, they are used to pop balloons bearing the likeness of Bowser Jr.