How Waves Break
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How and Why Do Waves Break?

This article will describe how waves form, how and why they break, and what the main types of breaking waves are. By the end, you'll know which type of wave break is good for a certain kind of surf.

A good surf session doesn't only depend on your superior choices in equipment or abilities as an athlete. There are other factors that come into play such as the weather and the wave quality on a particular day. At first, these factors might seem to be external, and therefore you might think that you have no control over them and you can't do anything about them.

Let us inform you as shortly as it could get: that is not the case. A surfer who knows how to read surf forecasts and the ocean floor has the upper hand from the get-go. Moreover, the surfer who understands the wave energy and why and how a wave breaks holds a fair bit of advantage over those that don't.

OMBE training almost wholly consists of understanding: part of it is about understanding your body, mind, or equipment, but understanding those without connecting them to the ocean will bear no fruit in the end. In surfing, rather philosophically, every other aspect gains meaning only in their relationship to the wave. Therefore, without developing a bond based on knowledge with the ocean, there's no real advance through the waves of progression.

Attempting no further to convince you of the imperative character of understanding the ocean, let's plunge into it and see how waves tend to break.

Breaking Waves

Before telling you all about the breaking waves, we first need to cover how the waves form in the first place, because in the end, and running the risk of sounding like a self-affirmed and self-appointed life coach, it's all about energy.

Yes, the natural world is made up of energy, and things happen when the energy of one entity (in our case, mostly the wind) comes into contact with another entity (the ocean): a transfer occurs between the two, resulting in a new form of entity—the wave. What happens next relies upon the capability (or capacity) of the latest entity to carry or transform that energy.

A life coach would have said that not knowing what to do with that energy and being unable to transform it into something useful is what breaks people. Unlike broken people, though, broken waves are not necessarily entities you want to avoid, especially if you're a beginner surfer.

Of course, we are blissfully unaware of the point of view of waves themselves. Maybe they frown upon each other, too, and gossip, like: "Wow, look at that sucker! It broke! It broke on the shores of Florida! Of all places!" But the secret lives of waves is a topic for another article.

How Waves Come Into Existence

Although it seems as if the ocean is a mystical place where huge waves are always present to remind us of the brevity and lightness of being (especially when you see all the creatures living in its hidden depths on a BBC documentary you can find on Netflix), it’s not really so. In actuality, it works in tandem with other natural phenomena like winds, earthquakes, and the gravitational pull of the sun and the moon. 

That's how waves occur.

A strong underwater earthquake (or a similar sort of explosive phenomenon) can create waves as huge as tsunamis. The ocean's indecisiveness whether to submit to the gravitational pull of the sun, the moon, or the earth creates tidal waves. In times of perfect alignment between the sun and the moon, these tidal waves grow to gargantuan proportions to the delight of pro big wave surfers.

However, the majority of the waves you need to know about as a surfer are due to the wind. When the wind blows over the ocean, its energy is transferred to the water due to the friction between the two. As a result, waves occur and start drawing water from the bottom to the wave crest.

Inevitably, as the strength of the wind increases, the wave height does as well. Similarly, when the ocean floor is steep, the wave will have more water to draw up from the bottom, and it'll quickly become big.

How Wave Breaks Happen

Remember how the wave needs to draw water from the bottom once it's formed? Well, more often than not, these waves travel toward a coastline, and approaching a coastline means that the ocean floor is getting shallower and shallower. Now, there's less water to draw and more friction between the ocean floor and the moving water.

So, what happens to all that energy when there's no way to feed it anymore?

The energy is still there at the back of the wave, trying to push it, but the friction at the bottom is pulling the brakes. As a result, the wave becomes a fastly moving bicycle when you pull the brakes on its front wheel: its back rises up; the only difference is that a bike is a solid object whereas the wave is, well, liquid.

Since there's no way the front of the wave can match that push due to the decreased water depth and natural brake system as a courtesy of the ocean floor, the back of the wave kind of explodes and overruns the front. In other words, the wave begins breaking by folding unto itself and starts losing all of its power, turning into smooth and mellow white foam you can observe near the shoreline.

Advanced surfers want to catch waves that are just on the verge of breaking as the wave still entertains a high crest and an explosive power at that point. However, for beginner surfers, the broken wave that turns into white foam is much preferable as it's quite ripe for learning the basics of surfing.

Types of Breaking Waves

Of course, not all waves break the same way the others do. The differences in wave length, the slope of the ocean floor, or the contact with other waves due to decreased wave period all play a role in the way the waves break.

However, we can still identify four main break types: spilling, plunging, collapsing, and surging wave breaks. Now, let's see what they are and how and why they happen.

Spilling Waves

Nearing some shores, the ocean floor will have a gradual slope that the wave needs to climb. As a result of that climb, the wave crest will get steeper and unstable. Due to that instability and turbulence, white foam will be spilled from the top of the wave.

As the wave nears the shore, the energy of the wave will diminish to a great deal and the spill will become a mellow one. This particular breaking process will also happen quite slowly, so the spill is not at all like an unfortunate accident you might suffer in a crowded bar.

As a result of all that slowness and mellowness, spilling waves break into gentle waves.

Plunging Waves

If you're a beginner, you're probably dreaming of doing some barrel rides one day. If you're an advanced surfer, just the idea of barrels leads to some temptation and you're itching to get hold of a surfboard now. Well, no matter what skills you have, you need to be thankful for plunging waves.

When the ocean floor is too steep and too unstable with sudden depth changes here and there, the wave energy will, gently said, go crazy. The crest will carry more power than it knows what to do with.

As a result, when plunging waves break, it's a violent yet beautiful sight to behold: the crest of the wave will curl further along the trough and create a tube to mouth-watering effect for us surfers.

Collapsing Waves

We're going to be very candid now: a collapsing wave is actually quite a boring one. It's the mid-ground between the above two and it's neither as gentle as the spilling waves nor as exciting as the plunging waves because it never allows tubes to form.

In other words, it approaches the shore like it's going to break magnificently, but it just collapses unto itself and creates lots of white foam.

Surging Waves

From a surfing point of view, the surging waves are as inconsequential as a wave can get since they have little or no power. On a surging wave, the wave crest barely exists, the flow is very slow and smooth, and there is a big chance that it won't break at all.

Moreover, despite their slowness, surging waves have a very fast backwash cycle, so you shouldn't mistake them for gentle waves. As there's no crest to speak of, the movement of water from the bottom to the top doesn't take very long. This particular attribute means that surfers won't only be finding it difficult to tap into the energy of a surging wave, but also that they'll be wiped out quite quickly because a fast backwash cycle is the number one enemy of standing in balance.

Wrapping Up...

Now you have a basic understanding of wave breaks and what geographical and meteorological conditions lead to which kinds of breaks. However, this understanding doesn't mean much by itself.

To make the most of it, you need to keep an eye on the surf forecast reports relevant to your location. In these reports, there'll be more accurate info about key external aspects of surfing such as the direction the wind blows, the wave period, and the wave height.

Once you're able to combine all these, though, you'll be able to pick your next surf spot with maximum efficiency.

Written by
Jeremy Dean
surf coaching