Jetpacks are a tricky thing. They've been on most sci-fi fans' wishlist since sci-fi became a genre. But unfortunately, as New Scientist points out, there are "the usual caveats that it is hard to strap enough fuel to a person to keep them airborne for more than about 30 seconds."
One solution: Swap out the idea of jet engines and achieve flight through jets of water.
The Jetlev Flyer, which will go on sale soon, crafts together a jetpack harness with two high-powered water hoses. As it slams water out of the nozzle, the pilot launches into the air. The gush is enough to send the pack at 30 m.p.h. and at heights of up to 50 feet in the air. And, as long as you fly over a lake, jetpack mishaps will hopefully end in splash rather than a splat.
Interested in buying one? New Scientist pegs the price at around $230,000.