Does anyone have any experience as to which material or boat maker is the best for sliding over rocks? A friend told me an experience of the Aire/Outcast boats, as fine as they are, do not slide over rocks very well when using them in real skinny water. In other words, they were very "grabby". I have rowed these boats but never under conditions where we had to slide over rocks. He contends that Maravia boats slide over rocks the best. Any opinions on this?