The hulls are made of EPDM/natural rubber like all Grabner inflatable boat skins, and not from PVC.
You get 7 years warranty on the boat skin. The long-term experience has shown that the lifetime of Grabner inflatable boats often is between 20 and 30 years. The boot skin is made of environmentally friendly ingredients and obtained by vulcanization firmest connections and a good abrasion resistance. Also, the UV resistance is very high, which is important if you want to use the boat in the sun. If anything happens, the EPDM boat skin can be easily repaired like a bicycle tube.
A Comparison to the UV exposure: If you spend the whole day in the sun, without using sunscreen, you get a sunburn. The same loads are also exposed to the boat skin. PVC boats usually only have a service life of 3 to 10 years on average and must then be disposed of as hazardous waste. A PVC boat skin contains many plasticisers to make the material flexible. These are hazardous to health and escape over time, making the material porous. If that’s the case, a repair is usually no longer possible. UV resistance is significantly lower for PVC than for EPDM. PVC joints are welded and often do not sustain high operating pressure. The “seams” then begin to loosen over time and fittings can detach.
More about this topic can be found here.