I had one of the original, old style, SB Otter's. I was always very careful to store it clean and dry. The mice got into the shed one winter and chewed two or three holes in it, the largest maybe 3". I was able to repair all of them, but it was the only patches I ever put on the boat.

I've never heard of anyone having this problem with a PVC boat. Is there something in the rubber they like to chew?