Beach cusps are concave seaward-facing features that are rhythmic in the longshore direction (Fig. 1.1). They consist of cusp horns separated by lower sloped cusp embayments where the sediment of the horn is generally coarser than that of the embayment. They are located in the swash zone, near the high tide mark, and form a series of undulations along the beach. Cusp spacing, the distance between consecutive cusp horns, is quasi uniform. The onshore topography is mirrored offshore with deltas forming at the base of each embayment and troughs forming at the base of each cusp horn (Fig. 1.2).