It looks dangerous and is, reportedly, incredibly expensive, but there is no denying the near-maximal awesome factor of the Jetlev Flyer. Power comes from a four-stroke engine in a small “boat” which drags in the water behind/below the flying harness, and to which it is tethered by a big yellow hose that supplies high-pressure water and prevents the operator from exceeding a safe altitude. [Thanks, Alan Dove!]