Tom,if you can, present the small dimension to the wind. I love it when people who have never handled a product become self-appointed experts. The mushroom head Velcro is damned tough to yank apart. It's not Chinese hook and loop and it isn't the regular type of Velcro. That's why I recommended GOOP which is elastic as well as adhesive. On really slick surfaces I carefully buff the area to be glued with 400 sandpaper. With Gel Coat a bit of car polish restores the gloss 100%
And Don, thanks for the temperature reminder.
When I sank a dozen RIV-NUTS into the roof of Quicksilver they were 1/4" x 28 stainless steel. Dipped into DEVCON-C compound then attached with a squeeze 24" handle tool. Poking holes in roofs is not for the faint of heart. Try making S pad mounts for a curved roof. I had to hire it out I did not have the skill. Red Loc-Tite was used to cure the bolts and nuts.
http://multimedia.3m.com/mws/media/1174470O/3m-recloslable-fastener-brochure-hr.pdf