If you have never heard of skim boarding, or think you can't skim board because you don't live near the beach this is for you.
Skim boarding (a smaller counterpart to a surfboard without fins) is basically riding a board of basically foam or wood on shallow water on or off the ocean.
Ocean skim boarding is similar to a surfboarding . On flatland like: Rivers and mainly lakes is for more tricks and spins like: Ollie's and 360's and jumps.
Wood is common on ocean and can work for flatland boarding. Foam boards, however more expensive are better for flatland skim boarding as they float better, which is useful as there aren't waves to push you. Wood works on flatland as well as ocean and is the cheaper way to go.