What is Wave Period?

Surfing has lots of slang associated with it, and even more technical terminology. Many people don’t realize that surfing all comes down to physics. It’s basically various forces interacting with each other. Now, we don’t want to bore you with all of the boring details, but what we’re looking at in this article is the term wave period. I’m sure if you’re into surfing, you’ve heard this term thrown around a lot.

What is the Definition of Wave Period?

Without over complicating things, wave period is the time it takes for two successive wave crests to reach a fixed point.  Understanding this will help you to understand surf forecasts.

Why is the Wave Period Important?

The larger the wave period, the longer the wave has to accumulate energy and travel faster. This means that the wave is more likely to be able to cope with local winds and currents. For surfers, this normally indicates that the waves are faster and better-peeling. It can be hard to spot waves with large wave periods with the naked eye, but they often indicate that better waves are coming.

What do the Different Wave Periods Mean?

When you look at a surfing forecast, you will be given a figure (in seconds) for the wave period. In order to help you to decipher this, we’ve come up with a handy little table!

Wave Period	What this means…
1-5 seconds	Poor surfing conditions and weak waves. The water will look unsettled and bumpy, but you will not be able to pick out individual waves.
6-8 seconds	Average surfing conditions with the possibility of offshore winds improving the wave quality.
8-10 seconds	Good surfing conditions. Medium-distance swells lend themselves for decent waves.
10-12 seconds	Very good surfing conditions. The waves generated will lead for a great surf session.
13+ seconds	Excellent conditions. These waves will be epic! Grab your board and head to the beach.

The Science Behind Wave Periods

There is more to understand about wave periods before you can quickly and simply decipher the surfing forecast. Waves can have two different types of swell: groundswell and wind swell. These terms refer to how the wave was made. Groundswell waves are created when waves are generated far away from the coast and wind swell waves are formed by local winds near to the surfing spot.

Usually, groundswell waves are better for surfing as they have had time to generate more energy, so they tend to break cleaner. Wind swell waves have the tendency to be more choppy and difficult to surf.

So, how does this link to ‘wave periods’?

Well, wave periods are sometimes known as ‘swell periods’, so this should give you a bit of insight into the link. Strictly speaking, the larger the wave period, the better the wave.  Waves with shorter periods are usually created by local winds, meaning that they are probably wind swell waves. Alternatively, the waves with larger wave periods are created further off the coast, often as a result of high winds and storm weather.

…And Remember

There is much more to a quality surf session than wave periods. That is why the forecasts include other aspects, such as; wind speed, primary swell, secondary swell, and the weather. All of these factors interact to change the quality of the surfing spot at a given time.

What a 10/10 wave is for an experienced surfer, may not be for one with less experience. Just because the forecast says that the waves are going to be epic at 10am tomorrow, does not mean that this is the best time for you to grab your board. What more experienced surfers regard as ‘flat’, is often a good training ground for beginners and improvers.

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