I'll second that vote for hypalon. The dinghy for our 32 Westsail was hypalon and it stood up to unrelenting exposure very well. Availability of a used vessel similar to mine in hypalon was my issue. I certainly do keep the vessel out of direct sun when possible and I hit it with UV protectant regularly. I will still assert, having worked on a number of inflatables, that the glued seams will fail long before the fabric if you don't just sit it out in the sun, clean it with solvents or abrade the surface. I'm just not seeing this cracking, hardening, failing thermobond seam issue on older zodiacs at all. It's not like I'm some shill for zodiac, I certainly wouldn't use a PVC boat as a larger boats tender or dinghy that got stored outside. However, if I was buying an older used PVC boat I would look for thermobonded tube seams. I'll fix almost anything, but when a tube seam fails the boat is trash as far as I'm concerned.