The Different Parts of a Wave

Even the most avid surfers have something in common: they may or may not know the different parts of a wave.

Sure, you’ve spent many afternoons at high tide catching the perfect wave.

But do you know what a wave’s trough is?

Do you know what a wave face is?

Or how to measure the steepness of a wave? 

In this guide, we’ll cover everything you ever needed to know about the parts of a wave. 

The Different Parts of a Wave

You may spend a lot of time on the water, but you may not always refer to the parts of a wave by their technical names.

You’ve probably used the word “crest” at least once in a sentence, but that might be about the extent of your oceanic vocabulary. 

There are two main parts of a wave: the crest and the trough.

We’ll talk about those, of course.

But you also may want to familiarize yourself with wave height, wave length, wave frequency, and other terms.

Let’s dive a bit deeper. 

What is a Wave?

To begin with the absolute basics, let’s first talk about what a wave actually is.

A wave is a disturbance in the surface of the water.

The waves we know and love to surf are breaking waves, not to be confused with internal or other types. 

Waves are mainly created by wind and by gravity, and are a direct result of energy passing through water.

Even smaller bodies of water, like the lake at your local state park, can have waves; these are usually generated by wind or some other disturbance, such as a boat. 

Larger bodies of water may have waves caused by both the wind and by the gravitational pull of the sun and the moon.

These are called tides, or tidal waves. 

What are the Crest and Trough of a Wave?

As you may have guessed, the crest of a wave is the top of a wave, and also how the height is determined.

The trough, conversely, is the lowest point of a wave. Imagine you have drawn two waves on a piece of paper.

The highest arcs are the crests. The “u” shaped center is the trough. 

If you’re headed out to the water to surf, you may be interested in the wave height.

To measure wave height, the distance between the lowest part of the trough and the highest part of the crest is measured. 

Before a wave breaks, you’ll be able to identify a few other parts.

The face of a wave, for instance, is great for surfing; it’s the part of a cresting wave that is about to become a peak, but has not yet done so. 

A wave’s peak is the area that’s just beginning to break.

It’s the highest part of the wave, and the first part to break.

A wave’s lip is one of the most powerful parts of the wave; it’s the section that begins to turn over, causing a hint of whitewater. 

In short, there are just a few basic wave parts.

The crest, which is the highest part.

The face, which is the best for surfing.

The peak, which is where a wave first begins to break.

The lip, which will almost inevitably toss a surfer off his board.

And the trough, which is the lowest point between two waves. 

What are Wavelength and Wave Steepness?

To fully understand wave steepness, we should first look at wavelength.

Wavelength can be found by measuring the distance between two identical parts of a wave.

For instance, the distance between two wave troughs or two wave crests.

The longer the wavelength, the faster that wave will be. 

The steepness, then, is the wave’s height to length ratio.

Surfers don’t need to be mathematicians, but it’s interesting to note that if that ratio exceeds 1/7, the wave will become too steep—it will begin to break. 

Curious how fast waves move across the ocean?

Well, that just depends.

Some waves will travel as slow as five miles per hour, especially distant from the shore.

Others may travel as quickly as 35 miles per hour or more. 

The waves that you see breaking on the shore are usually not just one single wave.

They’re the amalgamation of many different waves, usually which travel at different speeds.

Those waves just happened to meet in the right place at the right time, causing the waves you surf. 

Deep Water Versus Shallow Water Waves

There is one main difference between a deep water wave and a shallow water wave: shallow water waves are affected by the bottom of the ocean and deep water waves are not. 

A deep water wave is defined as any wave that exists in water with a depth that is more than twice the wave’s wavelength.

All waves transmit energy, but deep water waves are usually caused by wind. Tidal waves, by contrast, are shallow water waves. 

Know Your Breakers

There are three types of breaker waves. Some are spilling, some are surging, and others are plunging.

Let’s look at each and how the shape of the ocean floor affects the type of wave you see. 

Plunging breakers are waves that form on shores that are sloped steeply.

You’ll know these waves by their sudden height; as the wave suddenly approaches “higher ground” it will slow and climb.

The sudden loss of energy due to the friction against the ocean bottom will break the wave.

Spilling breakers are found breaking on shores that are almost flat; a very gradual incline is necessary for a spilling wave.

The energy carried by the wave is lost gradually. This means that the wave lasts longer and is great for surfing.

However, the waves aren’t quite as “dramatic” and exciting for surfers. 

Finally, surging breakers can be found breaking on extremely steep shores.

There is a sudden—almost immediate—loss of energy due to the drastic change in incline.

The result is a wave that breaks right onto the beach.

Surging breakers aren’t good for surfing, as they don’t last long enough.

Furthermore, there is no curl to the wave, giving surfers nothing to ride. 

What is the Best Type of Wave for Surfing?

Now that you know about the different parts of a wave, and the different types of waves, you may be wondering which is the best type of wave for surfing?

Well, you’ll find as many opinions on this as you will surfers. It will also depend upon how experienced you are.

With that said, though, there are some generally agreed-upon waves that can’t be beaten. 

Point breaks are waves that break around little “peninsulas.”

If there’s a bit of beach sticking out from the shore, and the wave wraps around the land just so, the result is a fantastic wave that will give you an ultra-long ride.

These waves are similar to what you’d see in a movie, but you may have to wait your turn to catch one!

Reef breaks break above rock or coral.

These waves are best for more experienced surfers; wiping out can be extremely painful and dangerous.

If you know your stuff, reef breaks can be very consistent and great for surfing. 

Plunging waves with “tubes” are excellent for surfing.

When a wave rolls through deep water, then enters more shallow water, it creates a tube shape that’s great for experienced surfers. 

Novice surfer? If you’re just starting out, look for crumbly waves.

These waves aren’t too steep or rough.

You can learn the ropes on crumbly waves or learn how to do a few tricks on your board safely. 

Do the Different Parts of a Wave Really Matter?

When you’re beginning to learn how to surf, it can be helpful to know the parts of a wave.

For example, knowing how to determine wavelength and wave frequency can help you find the best spots for surfing. 

As you learn, though, it’s just bonus knowledge.

Before long, you’ll be able to catch a wave at the ideal spot just by looking at it.

Don’t worry if you don’t know all the terminology.

The important part is to get out there and have fun!

Summary: Types of Waves

Learning the different parts of a wave may seem intimidating, but there are really only a few you need to be familiar with.

Knowing the crest from the trough can certainly help you hold a conversation with other surfers.

And knowing how waves break can absolutely help you find the best wave for your experience level. 

Get out there and experiment with different beaches to determine what type of wave suits your style best.

Every surfer’s preference is different, so don’t be afraid to find your own sweet spot!