I have not seen one except on this web site, let a lone paddled one. It looks like quite a rolling kayak. It is a prototype called “The Qaanaaq” is made by Water Field Kayaks in Japan, check out their web site. And US dealers, maybe you could import a few for us to try over here?
I saw this interesting site which if you scroll down has examples of great looking foam tunning for padding out the cockpit of your rolling kayak, I may try it this summer.
It uses a foam Masik, thigh braces and a great looking rounded back brace.