Types of Waves

There are four basic types of breaking waves: spilling, plunging, collapsing, and surging.

Spilling Waves:

Spilling waves are gentle waves with crests that break softly towards the shore. These waves break when the ocean floor has a gradual slope.

Plunging Waves:

Plunging waves break when the ocean floor is steep or has sudden depth changes. This is where you can get sweet barrels or enormous close-outs.

Collapsing Wave:

A collapsing wave is a mix of spilling and plunging waves.

Surging Wave:

Surging waves are the result of long period swells. As a result, the wave is slow, the faces are smooth and oblique, and the crest barely exists. These waves may not break at all. Breaking waves have a deep trough; surging waves do not.

As the waves travel farther away from the original wind source, they start to organise themselves into swell lines. “Wave trains” form and these inevitably hit the beach at the same time. These are what surfers call sets. Waves that are no longer affected by the wind that generated them can be referred to as ground swell. These are gold for surfers.

What Affects the Size of Swell in Open Ocean?

There are three main factors that affect the size of a wave in the open ocean.

  1. Wind speed – The greater the wind speed is, the larger the wave will be.
  2. Wind duration – The longer the wind blows, the larger the wave will be.
  3. Fetch – The greater the area the wind affects the wave, the larger the wave will be.

What Affects the Size at a certain break?

There are different factors affecting the wave size at a certain surf break.

Some examples include:

  • Swell direction – Will the break be “open” to the current swell direction?
  • Ocean floor/bottom (We will talk more about this next post) – A swell coming straight from deep-sea up onto a reef will generate big, barreling waves (see above). A long, shallow ledge up to the shore will slow down the waves and they’ll lose their energy, causing the waves to have less oomph.
  • Tide – Some spots are totally tide dependant.

So, know you have some of the basics under your belt. Stay tuned for our next #WaveWednesday when we will discuss how different ocean bottom affect the waves you surf.