A spit is formed through the process of longshore drift. As waves approach the shore at an angle, sediment is carried along the coast until it reaches a change in direction, such as a headland. The sediment builds up over time to form a sandbar that stretches out into the sea. Spits continue growing until reaching an area of fast water flow or change in wind direction. Sheltered water and salt marshes form behind the spit, providing habitat for wildlife.