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Surfers live for the opportunity to get into the water, but we should keep in mind that the waves are a gift of the winds. The winds themselves are a gift of the ocean, and there are things happening in the middle of the sea which will eventually bless us with the beautiful waves we know at our local break.
Basic Wave Mechanics
Wind occurs when warm, low-pressure air rises and cooler, high-pressure air rushes in to take its place. This may occur between warmer and cooler regions across the entire ocean basin, but the effect is also observed closer to shore as the rocky continental mass of the land is warmed daily by the sun. The air over the land is warmed during the day and when it rises, cooler air from over the sea rushes in to replace it. The rocky land also cools faster, so during the night the air over the land may become cooler than surrounding maritime air, and the winds reverse.As the wind blows over the water, there is friction between the surface and the moving air, which causes the water to ripple. You see the same effect when you blow on your morning cup of coffee to cool it, but there is a much greater area on the ocean surface, so there it potential for much more rippling. These ripples join together to form waves, and the wave are further driven by the winds, growing larger the further they travel (this phenomenon is called fetch). Although the waves may be slowed somewhat by friction in the water, they pretty much keep moving until something gets in their way, like the underwater shore profile at your local break.
Taking the Waves We Get
Although waves are formed and grow hundreds of miles away, the wind conditions right at the beach have a huge impact on the quality of the surf at any given moment. An on-shore wind, blowing from the ocean towards the beach, tends to push on the back of the wave, blowing the top off the wave and ruining its shape. This can make conditions in the break seem like the inside of a washing machine. The opposite effect can occur with an offshore breeze, which blows from the beach towards the sea. Since the wind is blowing on the face of the wave, it helps to shape it into the smooth, beautiful surface which is ideal for riding.
There are dozens of resources which a surfer can turn to in order to discover the conditions at their favorite break, but no surf report, whether on-line, from the local radio station, or even calling your friend at the shrimp shack is a substitute for actually observing the local conditions in person.
Learn More through at the beach observation
Most surfers will take a few minutes to sit and observe a few sets before they commit to getting into the water. Although the human eyeball will provide a wealth of useful information, some instrumentation can be helpful as well. A simple portable wind meter will tell you exactly what the wind is doing. Surf reports often give two wind speeds, steady and gusting. Gusting speed is the most important number since these intermittent blows, which may be twice the steady wind speed, can destroy ideal surf conditions.
One of the simplest and easy to use portable wind meter is the WeatherHawk MyMET Sport, which attaches to your smartphone. The app associated with this device can even let you record a picture of conditions to go along with the data you collect. The Davis Instruments Turbometer 271 handheld wind gauge is an exceptionally accurate but rugged wind gauge which is very easy to use. Our WM-350 unit is nearly a full-function weather station which will fit in your pocket.
- Wind occurs when warm, low-pressure air rises and cooler, high-pressure air rushes in to replace it.
- Waves are formed far offshore as the wind blows across the surface of the ocean. The more wind and the further they have to travel, the bigger the waves will be.
- Waves peak and break when they interact with the underwater shore profile at the beach.
- On-shore winds blowing from the sea towards the beach can ruin waves while off-shore breezes can help to shape them into rideable surfaces.
- Local observation using a handheld wind gauge is a great way to know what is happening at your favorite break.