As most skateboarders know, the design and materials of a skateboard are not designed to repel water. A board that gets left out in the rain, tossed in the pool or hosed down will likely never be the same again. If you think your board might be waterlogged, you will know by the way it looks, feels, and sounds when you try to ride it.
Take your board out on a quiet street, do a few ollies, and listen for the "snap" that a nonwaterlogged board makes. The sound should be crisp and clear. A waterlogged board will feel almost like dragging cardboard as you elevate, and the sound will be dull. It may also make a "creaking floorboard" sound.
Look for a warp or dip in the deck. Use a level to check whether the deck is straight. Examine the grip tape to see if it is fraying, peeling or discolored.
Pay attention to the state of the wood. Signs of waterlogging include chipping and splitting. If the glue loses its tackiness, all seven layers can crack and the board may split in half.