The Water Jet Pack uses the Power of a jetski to lift a person in the air and provided awesome fun. Ever since the famous James Bond Scene people always wanted to have and build something like that. As the rocket powered versions always kept quiet dangerous this really seems to be a much safer and actually even more fun way of achieving that.
So now you want your own? here you go: Jetlev Aquaflyer
Meanwhile there was also an evolution of this jet pack into the Flyboard, which has the hoses at your hands and feet allowing for even more radical maneuvers.