Hull and Below the Waterline

The hull is the body of the boat. The waterline is where the hull meets the water surface. The draft (or draught) is the depth of the hull below the waterline — critical for knowing what depth of water you need.

The keel is the structural backbone running along the bottom of the hull. On sailing yachts, the keel extends downward to provide stability and resist sideways drift (leeway). The rudder, mounted at the stern, steers the boat and is controlled by a tiller or wheel.