Doug, if you're really into not penetrating the shell, and all you're mounting is canopy anchors, try the following:
with either actual bolt rope
or track bullets
* as an anchoring device. It can be bent to fit curves, but make sure you curve it slightly down from one end to the other or from the center down so it doesnt cache water. The link I included isn't the only source - many aluminum distributors stock it in 12-20 ft lengths
, so buy as locally as you can, or maybe have it cut down to 6' to ship UPS. Track is also available in more flexible plastic.
VHB tape of the appropriate sort to attach the track to polyester gelcoat. I can't help you with the exact type, but 3M has good support and definitely can. Keep in mind that you'll need a foam layer because your spacing between the track and the shell isn't going to be consistently zero. Make sure you get a few product numbers that could do the job, as not all of the types are sold
in affordable quantities. McMaster-Carr
are possible sources among many others. If you're wondering about durability, keep in mind that VHB tape is what is used to hold the panels to the structure in passenger rail and commuter buses.
*note that track bullets slide independently - if you need tiedowns to maintain spacing despite being pulled at an angle, try installing small tieoff grommets in the webbing of a length of bolt rope.