This just seems like something someone with a lot of capital did just because they could. It would probably be safer and more fun to buy a boat and an RV.
If I were a mega-millionaire, I would own one just to be able to point it at a boat ramp, start screaming "MY BRAKES ARE OUT!!!" and roll that thing into the water and float away.
the looks on peoples faces would be soooooo worth it.
I saw this on TV. The show "Extreme RV's" had it. If I remember correct, it was made by a family that makes a commercial version of "Ducks" large ATV's that run tourists into lakes or rec areas.
If I had the cash, would love to have a smaller version, about 32 foot long.