Alaska, Mexico, and everywhere in between.

How Waves are Made

Here in Sayulita, Mexico, one of our favorite pastimes is surfing, but to surf you have to have waves. My dad asked me to write a paper on how waves are made, so I turned to the Internet. I looked at a couple sites and they all said the same thing, wind makes waves. Most good surfing waves are made really really far offshore. Local winds can make waves too, but not very nice ones usually. Low pressure systems usually create better waves because in deep low pressure systems there are higher wind speeds and more waves are generated from the power of the wind. This wind makes friction which helps to form energy waves which travel thousands of miles before hitting a coastline or reef. If the winds created in low pressure systems blow for a really long time over a large area of water, the swells will be bigger because of all the energy collected. The size of the swell is affected by three different variables, the velocity of the wind, it’s duration, and the fetch, or the distance the wind blows over. There are “ground swells”, and “wind swells”. “Wind swells” are swells formed from local winds and they tend to be choppy. “Ground swells” are swells generated far off the coast and they are usually well formed, but they can be even better if there’s a gentle offshore breeze. An offshore breeze, means a breeze coming from the shore to the waves, they help the waves stand up. Swell height refers to the height of the waves in deep water, Knowing the swell height helps surf forecasters determine how large the waves will be. Swell direction is the direction from which the swell is coming, it is measured in degrees and helps the forecasters tell where the waves are going to be good. Swells perform differently at various breaks, a break is a place where the waves break well enough to be surfed. There are three different kind of breaks, a beach break, a reef break, and a point break. Beach breaks are the most common, but also the most difficult to forecast because of the random qualities of the the ocean floor which is always changing. Next is the reef break, reef breaks have a rock bottom. They have deeper channels next to the shallow water which gives a good form to the wave, and they can often force waves quickly from deep to shallow water which makes large and hollow surf. Point breaks are breaks in which the waves bend or break around a specific point, usually resulting in consistent and good shaped waves. Point breaks are usually formed around river mouths with loose rock bottoms. Here in Sayulita we have a beach break near a river mouth.