Diagrams and images are used to explain the formation of waves, their swash and backwash. Constructive waves are flat and low with limited energy. This energy washes material up the beach to create a gentle beach. Destructive waves have much more energy and are higher. The backwash is very strong and removes material from the shore to create a steep beach.
While watching the clip students could complete a two column table which allows them to compare the two main types of waves; constructive and destructive. Side headings such as wave height, wave frequency, strength of swash, strength of backwash, beach composition (sand or shingle), other landforms (berm/longshore bars) would focus attention on the important differences. This would allow them to easily answer an exam question such as 'Describe the differences between constructive and destructive waves'.