You can masturbate in the shower, bath tub or a Jacuzzi.
Using the shower head only works if it’s one you can hold in your hand. You can direct the water stream directly on your penis, possibly moving it up and down the shaft and the tip of your penis.
You can grasp your penis as you normally do and move up and down, using lots of soap to increase the pleasure by making it all very slippery.
In the bath tub you can lie on your back, positioning yourself in such a way that your penis is directly under the flowing water from the faucet.
When you are in a Jacuzzi or hot tub water that flows from the jets can have a wonderful effect when it hits the hot spot. Discover the distance that places the right amount of pressure on your penis.