I just got the spring 2011 catalog from Texas Towers, the people who supply aluminum tubing to the amateur radio community, and also to those who build aluminum-framed kayaks. Tom Yost lists them on his list of suppliers. Apparently quite a few people have followed up and bought their aluminum tubes. In the intro to this edition's tubing list is the paragraph titled Good Stuff! It reads:
" In addition to thousands of amateur antenna builders across the USA, our tubing customers include major amateur radio antenna manufacturers and dozens of smaller antenna manufacturers. Beyond that, our aluminum tubing finds its way into an intersting assortment of other commercial and home-built applications: telecope trusses, folding kayak frames, furniture frames, wind chimes, automotive radiators, and intercoolers, and more . . ."

There it is. They apparently get enough kayak builders ordering that it has made an impression.

PGJ