Spray skirt
From Trail-Finder -- Dedicated to getting you outside
A spray skirt is a water-resistant or waterproof sheet of oval-shaped fabric which fits snugly around the cockpit cowling on a kayak. It has a hole near the back, which can be adjusted in some fashion, which allows the kayaker to fit it snugly around his or her waist. When a spray skirt is in place, waves breaking over the kayak result in little or no water seepage into the kayak. Also, if the kayaker rolls, it's possible, with practice, to do an eskimo roll to right your boat, while still keeping the inside of the boat relatively dry.
IMPORTANT: There's a loop of webbing at the front of the spray skirt. This loop must always be on the outside of the kayak, never on the inside. If you roll and need to get out of your kayak, you grab that loop and the spray skirt pops right off. If the loop's accidentally on the inside, you may not be able to get the spray skirt off in time to avoid drowning.
