Hey Tom,
When I first saw people doing this a few years ago, I thought it was the dumbest thing... However, upon further observation and speaking with practitioners of the art, I've come to appreciate how great a form of exercise it can be... The key is to be able to not look too silly doing so, you look pretty damn good in your pic, I must say... (grin) I'd definitely have to find myself a remote place to practice for awhile, before taking the risk of embarrassing myself in such a public fashion...
No way I could consider carrying a suitably-sized SUP on my boat, but I've read some pretty good stuff on the inflatable ones that are out there now... John Reid on RAMBLE mentioned years ago, that he was very impressed with his Airis inflatable kayak from Walker Bay, which was one of the first that employed the drop-stitch technology to increase rigidity... It's standard now on all the ISUP's, they seem to have perfected it to the point where they come reasonably close to the stiffness of a regular paddleboard...
If anyone has any further experience with these, I'd love to hear about it, as I'm seriously considering pulling the trigger on one of these things between now and next summer...
best regards,
Jon