It's great how hobbies can overlap.
We used 2" wide strips of Hypalon left over from a "hull reinforcement kit" from my Folbot kayaks.
You put strips along the outside of the hull where the inner aluminum frame parts meet the hull. Then when you scrape over a rock, the strip takes the damage and is a sacrificial, replaceable part.
I also used up most of a kit repairing my badly damaged, NEW Citibot skin. Hadn't put the sacrificial strips on yet and came close to trashing the hull. Gory details in case anyone is interested. Don't try this at home. �;)
http://home.comcast.net/~jrburch_h/folbot/mymods/citibot_repair/citibot_thrashed.html