Snowmobiling blues...

What are you going to seal the plywood with to make it weather proof? Is it exterior grade marine plywood?
I'm not sure exactly if I was going to treat it at all. I've got five 9/16 bolts on each one that come out quick. I was just kind of thinking about storing the plywood inside most of the time when not in use. I was probably going to need to take it off anyways so the deck would be light enough to handle.