What materials are whitewater rafts made of?

Inflatable rafts are generally constructed of either Hypalon rubber, or Poly Vinyl Chloride (PVC). Both of these materials are considered "Bomb Proof" and are used in commercial rafting operations. PVC tends to deteriorate quicker under high UV exposure at altitudes.

PVC employs the use of seams where as Hypalon rubber is a seamless weld. Hypalon is more expensive, but is made to last a life time unlike PVC.