Longshore Drift

Longshore drift is the process of the transportation of sediments (usually sand). The sediments go along the coast at an angle to the shoreline, which is dependent on the wind direction, called swash and backwash. Because of all the sand being moved, it causes a sandspit at the point of a bay, river, etc. Humans have created, in certain areas, breakwaters, so that the sandspits don't form in the harbor.