Wave refraction

This process tends to occur on discordant coastlines, where there are headlands and bays, protruding different distances out into the sea.

In deep water, the waves approach the coastline as normal. Nearer the coastline, frictional drag affects the waves because of contact with the seabed in shallower water. This causes the wave to realign with the coastline, so there is concentration of wave energy around headlands, and dissipation if energy in bays.

Distribution of wave energy in refraction is determined by topography and geology of the coastline. Therefore, it is important to acknowledge that it is interactions between the two which shapes a coastline, not just one.