A boat part is any component of a boat that helps it to function. The STEM is the foremost part of the boat, and is usually the longest and strongest part. The KEEL is the central structural component of the boat, running from the bow to the stern. The PROW is the front part of the boat, and is often decorated with a figurehead. The HULL is the main body of the boat, and is usually made of fiberglass or wood. The gunwale is the upper edge of the boat's sides, and is used to attach the boat's deck. Finally, the RUDDER is a flat piece of metal or wood attached to the stern of the boat, and is used to steer the boat.