Very interesting, creative and resourceful. But the lightweight tarp skin would die a rapid death on any water body other than a placid lake and grassy shoreline. Drag it over rocks even a few times and it would be a goner. His later polymer skin model is likely more durable. Integrity of the skin is critical.
I have a couple 17 ft. Klepper Aerius II kayaks with canvas decks and heavy duty hypalon rubber bottoms. It's tough stuff that's held up for decades. I've taken them on rivers throughout CO, UT, WY and AK. Instead of using foam like many kayaks and canoes, the Aerius models use rubber sponsons or tubes that run along the sides from bow to stern. When inflated they tighten the skin to the frame and add buoyancy making the boat almost impossible to turn over. The boats disassemble and are packed into two bags for transport in the trunk of a small car.
The Klepper kayaks have crossed all the oceans and seas of the world and are used by military forces. Here are some images that show the various uses:
https://www.google.com/search?client...mg.OIfYX1jSn2M