What Type of Waves Are in the Surf Zone?

Long Period Swells

• A group of waves stacked in a close succession is referred to as a "set." "Period" refers to the time between waves in a set. The power, duration of a storm and distance of a storm from where the waves it generates break are what determine the period. As power increases, so does wave speed and period. As such, swells created by enormous storms (usually in the far Northern or Southern Hemispheres), which direct waves at coastlines thousands of miles away, create what are known as long period swells. Because of the long distance these waves must travel to reach shore, faster waves will catch up with slower ones to combine into a single wave. Over the span of several days, this trend will organize the waves into clean lines that are often described as looking like corduroy fabric when seen from the coastline. Containing immense power, these waves break with crushing ferocity when they reach shallow water.

Short Period Swells

• The opposite of a long period swell is a short period swell. These wave systems are created by small-scale storms situated close to the coastline on which the waves will break. Because of the relative weakness of the storm and the short amount of time the waves in a set will have to organize themselves into clean lines, the distance (period) between waves in a set will be very short. When short period swells reach shore, they tend to look chaotic, messy and turbulent, standing in direct contrast to the large, clean and beautifully organized lines of a long period swell.

Beach Breaks

• Bathymetry is the study of the bottom contours of the ocean. The dominating bathymetry of beaches is that they taper off from the shore at a gradual decline, gaining depth gradually. As a result, when waves reach a beach, much of their energy is lost dragging along the ocean floor until it is shallow enough for waves to break. When they do finally break, waves over a beach are often mushy and lacking any serious power because of the energy lost reaching the shore. It should be noted, though, that all beaches are different. Those that feature a steep shoreline will exhibit significantly more powerful waves than beaches that are very flat.

Reef Breaks

• In stark contrast to the gently tapered bottom contours of most beaches, shallow reefs most often rise abruptly from deep water. What this translates to in the surf zone is that incoming waves are able to ride through deep water right up to the reef's edge, losing little or no power from dragging along the bottom. When a wave hits a shallow reef with most or all of its power retained, it seems to suddenly "jump" up from the ocean's surface and unleash the full brunt of its energy when it breaks. It is for this reason that skilled surfers consider the best waves in the world to be reef breaks.

Point Breaks

• Yet another type of wave found in the surf zone is the point break, so called because the wave begins to break at a certain point and will create a long tapered wall that will peel for a great distance. Point breaks occur when the angle of an incoming swell is less than perpendicular but greater than parallel to the angle of the shoreline or reef edge.