While going to the toilet, side backwards facing the cistern. When completed, flush the chain and vroom, this gives the impression of being in the mediterranean on a jet ski.
While sitting in a bathtub or shower filled with 2-3 inches of water, let rip a huge fart and you create a. Jet Ski. If your fart is big enough you can create a rooster tail.
To bury one's face in the breasts of a woman with A cups while making a raspberry. Basically, an attempt to motor boat on a woman breasts that aren't at the size necessary to motor boat.
Charlie smiled as he quickly shoved his face into Diana's breasts and made a motor boat sound shaking his head. Unfortunately, Diana lack the proper equipment and he was left with a jet ski.
Similar to the motorboat....it is where a guy and a girl face eather other then she sits down on the ground in front of him. Next, as he stands over her, she proceeds to "motorboat" his boner and balls with her face.