They have a foldable one at REI on Westheimer. It looks like it is made our of core-plast. (the plastic stuff that looks like cardboard). Not nearly as cool as this one but it is something a little different.
I keep hoping to see one like this in person sometime. I have trouble enough keeping water out of my " sealed" yak, I can't imagine trying to keep up with one like this out on the flats all day. But, it sure makes draining easy!
You don't think you could say "I'm on a boat" literally anytime if you had that?
Or it won't float?
Someone had a 3 piece one on CLAPs at an event one time. Wasn't exactly like that, but same concept. Could insert extra pieces to make it a tandem.