The hull of the Classic consists of the same material as a wild river raft. It’s a very resistant material and not easily damaged. Nevertheless, it could be punctured by sharp objects below the water surface such as barbed wire or broken bottles.   The FHII consists of nylon with a Cordura cover, which is even easier to patch. If you run out of luck and air, the hull can easily be repaired. The glue needed has a very short shelf life, so we don’t add it to the package, as it would probably dry out before you need it. You can use a small tube of Seam-Grip for a semi-permanent fix; you’ll find this in most outdoor shops. Afterwards, order a repair patch and glue for a permanent fix.