Just a thought, I wonder what pressure is involved, enough to strip flesh from bone if you got in the stream of water? Maybe I'm barking up the wrong tree but just think about it, the end of a garden hose will lift off the ground a couple of feet if turned on fully, but there is little weight in that.
A 4" fire hose will knock you around if turned on fully and from experience, can lift you a little into the air but how high are these guys going.
Under the water isn't a problem except, when, because your not wearing goggles, the retina in the eyes are displaced.
It would be like any of those gimmicky fads that have taken place over the last 6 decades or so but a dam site dearer than a Hoola Hoop.
Great as an amusement park attraction or a tourist attraction at a resort but I would have thought other than the rich and famous it would be absolutely useless to us Pleb's, no different to tits on a bull!
It just dawned on me there is a scientific trick to this, to every action there is an equal and opposite reaction.
The actual hose, setting aside the need for it to act as the medium to transfer the water up to the equipment the guy is wearing, is the means whereby he stays aloft as the water is causing it to become rigid lifting the person in the air.
OMG where's Fact Hunter when you need him.
Sorry about my rant for the day, I will have to stop picking up durries thrown out of choppers (site video clips)!