Destructive waves are usually found in more exposed bays, where they build pebble beaches. Destructive waves are more common in winter than in summer. Although a destructive wave’s swash is much stronger than that of a constructive wave, the strength of a destructive wave’s swash is much weaker than its backwash. This means that destructive waves can transport beach material back into the sea and lower the height of beaches in winter. The force generated by a breaking destructive wave can also erode a headland.
Destructive waves destroy beaches. The waves are usually very high, have a short wavelength and are very frequent. The wave has a steep front and is typically over 1 metre high. The backwash has less time to soak into the sand. As waves continue to hit the beach there is more running water to transport the material out to sea. As the wave approaches the beach it gains height and plunges onto a steep beach so does not travel far up the up it.