The Hoverboard by ZR brings another dimension to water sports lovers. Attach the 60′ hose and kit to a watercraft and fly 20 feet in the air up to speeds of 15 mph. Cowabunga! The complete kit runs close to $6,000, so make sure you really want it or it’ll end up in the corner of the garage somewhere. Right next to those other expensive toys you used once and never used again.