Spraydecks are used to prevent water getting into the cockpit of your kayak. Nylon decks are generally easier to put on and take off your kayak and aimed more at the beginner. Neoprene spray decks offer a tighter, dryer seal and water will run off the deck easily and not pool on your lap. Neoprene decks come in a range of specifications depending on the type of paddling you take part in. For example, Spraydecks for touring do not need to be as tough/reinforced as a deck for white water.