FLUDD aims for the sun.

You begin the game with the normal and hover nozzles. You'll unlock other nozzles as you play through the game, but they're only available for the area in which you unlock them. The attachments are packaged in white square crates. Blue is hover, gray is turbo, and red is rocket. Once you've found a solid crate within an area, you'll be prompted to save. Once you do, you'll be able to open all crates of that color from the current episode onward in the area.

Normal Nozzle - You'll always have access to this nozzle. By pressing R, you'll shoot a stream of water forward. Completely depressing and holding R will allow you to aim the stream. You'll need to load more water after about six seconds of continuous use, but letting off the trigger at any point while standing in water will fill up your tank.

Rotate Control Stick 360 Degrees and Press R
Mario spins and sprays droplets of water in all directions. Holding R right after performing a spin jump can increase the duration of the spray. This is normally more useful for cleaning up sludge, but it's useful against enemies in some situations.

Press R Deeply, Then Press Jump Immediately Afterward
Although it has limited applications, this technique is unique and worth mentioning. While moving, pressing deeply on R and then A immediately afterward will produce a shotgun-like blast of water. If you depress the right trigger until it clicks with the right timing, you'll propel yourself into a back flip. This can be used as a substitute for a turn-around jump in some situations, or to stylishly hose a group of advancing enemies.

Press R While Hanging on a Rope or Wire
You'll begin to rock Mario back and forth, eventually building up enough momentum to begin spinning on the wire. Hit the A button to let go and propel yourself very far in the direction you were spinning.

Hover Nozzle - The default secondary nozzle, you'll have access to this mode unless you pick up another from a crate. Arguably the most versatile nozzle, you can use the hover nozzle to extend your jumps and effectively clean or attack

Hold R
Depress the R button and Mario will move upward and forward for a maximum duration of four seconds. The primary use is to guide your jumps and spray directly beneath you. Many enemies can be quickly and easily be sprayed and squashed in this manner.

Hold R While Swimming
The hover nozzle will allow you to move faster while swimming. Depress and release the button at regular intervals and keep tapping A for optimal speed.

Turbo Nozzle - Although a lot of fun for just jetting around in the water, the turbo nozzle is a specialized instrument for specific situations.

Press and Hold R
When the R button is depressed, your FLUDD gauge will show a rising red indicator indicating the point of activation. The harder you press, the faster it will fill. When it does, a burst of water will propel you at high speeds over land or sea. While it boasts great performance in the water, laying into the turbo on the ground is not normally advised because of a very poor turn radius. Slamming into most objects will stop you cold (without any injury), but you can bust through certain objects while jetting to reveal a hidden passage or stash.

Rocket Nozzle - As the final nozzle you'll gain access to, the rocket nozzle should be worth the wait. There are numerous shines that require the use of the rocket, and you can spare yourself difficult or time-consuming vertical climbs.

Press and Hold R
As with the turbo nozzle, a red indicator will let you know when it's time for ignition. As long as you're not submerged in water, you'll be fired straight up into the air. You can gain additional height by jumping just before activating. If in water, a small jump right before the rocket fires will allow you to boost right out.