Dock maintenance

[uschisk]

Hello all - our island camp has a standard dock that is pulled up in the winter. I believe it was new in 2007 or so, before we bought the camp. We have never done anything to the wood, and now I am wondering if we should have? We are starting to see some breakdown on the surface, and this week I have gotten splinters as I was reaching across it. How do people take care of their docks? Whatever we do would need to not be slippery. How long should these wooden sections last? Thank you!