Photo of Bluebell Woods in Sussex Photo of Bluebell Woods in Sussex

Pacific Island Navigation

There was a near perfect ripple map on a very windy West Wittering beach yesterday.

The different wave patterns on each side of an island allowed Pacific Island navigators to sense land that was invisible.

When you know the patterns to look for, they can be spotted in vast oceans, small puddles and everywhere between.


I have been sent a lovely example of waves crossing over and creating an interference pattern on the downwind side of a miniature island. This bending of the waves, or ripples in this case, is caused by refraction and diffraction as the waves pass close to land and over shallow water.

Even on this miniature scale it is easy to see why the water on each side of a larger island does not look or feel the same to ocean navigators.

Refraction and diffraction patterns around miniature island. Image credit: Alan Gibson

You might also enjoy:

How to Read Water

How to Read Wave Patterns at the Coast

How to Navigate Using the Sea

The Effect of Wind on Breaking Waves