Re: Need a decent boat cover.
Any tarp will last much longer if it's supported properly. I use PVC to make a center tower and several outward supports to keep water from accumulating on the tarp. I get much better life out of the silver tarps, they seem to reflect much more light and last far longer. I also add grommets where needed to properly secure the tarp. The best tarps are canvas or heavy vinyl. Or even Tyvek if you can find or afford them.