Understanding Waves

Surfing conditions at a particular location or "break" that is known for surfing are almost never ideal all the time. Wind blown consistently over a large area of fetch (open water), generates waves. These waves use a drafting effect similar to racecars and cyclists to travel vast distances efficiently. As waves near their ultimate destination (land), the bottom of the wave begins to run aground as the water becomes more shallow.

There are two primary factors that contribute to the general characteristics of waves at a particular break: the "swell window" or the exposure of the location to wave-generating areas of fetch, and the structure of the ocean floor (composition, shape).

Swell Window

The swell window determines the potential of a break to receive waves. In general, the western coast of any continent usually has better breaks since winds (and, therefore, waves) tend to travel from west to east.

Coastlines that face east or south (in the Northern Hemisphere) or north (in the Southern Hemisphere) that are exposed to tropical storms and hurricanes can also be surfable on a consistent basis.

When waves break along a section of coastline at an angle almost perpendicular to the land, these special locations, known as point breaks, can produce very long-lasting waves that can be surfed for several hundred metres.

The two main types of waves for surfing (apart from the pointbreak) are:

• the reef break: waves breaking over a coral reef or rockbed
• the beach break: waves breaking onto sand bars

Ocean Floor Structure

The structure of the ocean floor is the biggest factor that determines the broad characterists of waves at a particular break. For instance, there are beach breaks (soft sand bottom) that generate slower, mushy waves and reef breaks (coral reef or rock bottom) that tend to generate faster, more powerful waves. Based on the structure of the ocean floor, a location may break better on a particular tide, say, an incoming high tide or a low-low tide.

Other Factors

Local wind conditions, water temperature, solar radiation, the crowd factor, hazardous aquatic life, water pollution, and aggression of local surfers are other factors that can have impact on the experience one might have surfing at a particular break.

The availability of free model data from the NOAA has allowed the creation of several surf forecasting websites. These automatically combine the above variables into a presentation of how good the surf will be.