M_Boats: Roller

What have you used for beaching a M15? What type of roller or cushion to protect from small rocks in the shallow water when beaching. I see West Marine has a roller but its inflatable and I don’t see that working. Actually theirs is for the beach sand. This one has to sink and stay on the bottom so the boat rolls up over it as it moves towards the shore in shallow water, less than one foot. Thanks. I was wondering about PVC, like 4” PVC but it seems that it would have to be covered in something so the boat would not slide off of it as it rolled forward. Maybe a carpeted 4”x4’ PVC tube would work. Got any ideas.