Masturbation aided by water.
Doug: "Yo Yo Yo i was wackin it in the tub with the water flowing over my wang-no hands needed!"
Chantel: "Yeah G, i was working myself with the showerhead this morning. Those pulsating jets get the job done."
Doug/Chantel: "Hydrobation is the best!"
The Male art of masteurbation, except using a strong, concentrated stream of water. Usually, these water jets work better when warm. These streams can be found in pools, jacuzzis, showers, and many other assorted devices that use water.
Bro #1: Yo dude get out of the pool nobody else is in there anymore.
Bro #2: Hold on bro im hydrobating, this water jet is awesome!
Bro #1: Aight man, hydrobation is pretty intense so ima let you be.