I knew you would come up with a good suggestion!
This would provide a compact solution to those who might be concerned about a yak on their vehicle. With a full size pickup I don't have that problem.
Although an inflatable would require inflation, 50 cents at any Mobil will do the trick in a minute or two and it will remain inflated for the season like my pontoon boat.
I have a feeling that the ability to use air pressure for rigidity will reduce the weight dramatically. Haven't found it yet though.