Whenever waves meet shallow water, the patterns change. We can use these new patterns as clues to the depth of water.
It doesn’t matter the size of the waves – they can be ripples, waves or swell – the key thing is that the patterns will change when waves of any size meet water that is a comparable depth to the wave’s own height.
Study the patterns in the video above that I took in Mauritius recently. Make sure you watch until the end.
The fisherman walks from the shore through water that gets deeper steadily and then more suddenly. He then steps up onto the reef and walks in water that is only inches deep.
The first thing you’ll notice is that there is calm patch where the water is extremely shallow. This is the reef.
If you watch the video a few times, you’ll get to know the depth and the patterns better until you can spot the changes even where the water suddenly gets deeper next to the small reef ‘wall’.
The small waves form patterns that act as a map or chart of the seabed.
When waves meet water that is too shallow, they topple over. A wave breaks when its height is 3/4 of thew water’s depth 3/4
You might also enjoy:
The Difference Between Ripples, Waves and Swell
How to Read Water – The Book
