They did a segment about this on the UK show "The Gadget Show" a while back, the female presenter Suzy Perry (I think...) tried it out (don't remember what season or episode.) Based on what I saw there, this is basically something that works best for guys - who are really in shape, because it's a massive workout to get it to move. Bodyweight and muscle power also help, she was struggling to keep it going without sinking.

So it's not just "bounce slightly and soar away across the water", it's more like "pump your ass off with zero break time or you'll sink like a stone" - and no, it doesn't allow you to get going once you sink without a new standing start from the beach.

Definitely not for me, in other words. A) you look like a certified jackass on one and b) you have to work your ass off while doing a).