The two-part flexible epoxy from SA has been around for a number of years; a 3M technology spin-off. The stuff is absolutely fantastic. It's sticky like aquaseal, but doesn't peel, cures faster than most one part products, stays flexible and won't crack (have used it as a firewall gasket sealer on the truck)... great for wader repairs, gluing cracked cork, butt caps that fall off, boot repair, patching float tubes/pontoon boats/zodiacs, etc. etc. etc. etc. The stuff keeps great and doesn't get crusty and hard like an opened tube of aquaseal.