Water Jet-pack/Board

Okay, these inventions aren't exactly simple but I felt they needed mentioning because they are by far the best I've come across so far. This invention is an engine powered jet pack which pulls water up through a pipe, which hangs in the water behind the jet-pack, then propels it through the water nozzles and lift the user above the water up to 10 meters depending on weight and size! The only issue is that this is a pretty pricey piece of equipment, the RRP is roughly $130,000(VAT included). For more information on the Water Jet-pack please visit http://www.jetlev-flyer.com/
And to see it in action check out the video here --> http://www.youtube.com/watch?v=im1iNq02Kz0