Meet SeaBob. Not your ordinary Bob, whom you might confuse with the guy from select bad jokes, but instead a waterbound device that transports (read: drags) you through and below the open waves of your favorite boat-infested harbor.
The SeaBob essentially works as a self-propelling riding vehicle and is roughly akin to a jetski. You grab hold of two "controlgrips" which help accelerate, slow down and brake. You literally put your body into operating SeaBob, shifting your weight around to steer and dive, à la a Segway. An electric jet stream system provides the thrust in combination with a 5-horsepower motor. The best way to describe the overall experience is to think of yourself as a big fish moving through the ocean at a decent clip of speed.