"The waves we surf always travel in groups of seven, and the seventh wave is the biggest of all." Fact or myth? We debunk this phrase with a bit of surf science and speak from experience.
Myths and Realities in Surf Science: Do Waves Come in Sets of Seven?
You've probably heard that claim from your soul surfer friend or the old sea dog you met that one time coming out of the water almost at night. You've probably already realized it, but that phrase is one of many urban myths in surfing. Waves don't come in groups of 7, and the biggest one isn't the last.
The truth is that the frequency of waves cannot be predicted, as they originate from the capricious action of the wind on the sea surface. And wind, as we know, is produced by temperature differences on the Earth's surface, generating air currents from warmer to colder areas as a way to maintain equilibrium in our atmosphere. Once again, we find that nature tends toward neutral states, and thanks to that, waves and surfing exist (among many other things). If you want to know in more detail how waves originate and how to understand a surf forecast, click here.
The Journey of the Swell: Understanding Wave Physics
Returning to the topic of waves, while their origin is indeed disordered and chaotic, once they form, they tend to settle into traveling groups. Disorganized waves traveling thousands of kilometers across the ocean organize themselves into more or less predictable "packages," and the further that swell has traveled, the more predictable they are, and the more likely the waves are to be long and peeling. What we call a "perfect surf day."
Why then do people say they come in sets of seven? – Surf Science
Englishman Tony Butt, a guru in the study of wave physics and surf science, has described that the waves observable on a good day at the beach usually arrive in groups of 12 to 16 waves.
Which is the biggest wave in the set according to marine physics?
In these sets, as often happens in group physics, the largest wave tends to be in the middle of the group, a crucial piece of information for when you are sitting in the lineup and see a set of waves approaching on the horizon. The first wave in the group is very small, the next is larger, and so on until the largest wave in the middle of the set is reached. So, if there are 14 waves on average in a set, the seventh wave is the largest. Then, they gradually become smaller, finally returning to calm.
This would be the possible basis for the popular saying that waves come in sets of 7, by not taking into account the decreasing waves and only focusing on the increasing ones.
Applying Surf Science in Your Next Session
As a set of waves approaches on the horizon, a kind of dance begins in the lineup between those who want to catch the biggest possible wave, those who want to avoid the wave, and basically everyone else who doesn't know what to do. You already know, patience in the lineup, you already know a bit about surf science and that the biggest wave in the set won't be the first but will normally be located in the middle of the group, and that groups come in waves of 12 to 16, whether you want to avoid it or catch it.
With love, #AlwaysFree
Flysurf.
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Sources:
Surf Science: Tony Butt.
Yoroboku.
Journal of physical oceanography.
