Surfing is a sport that many people enjoy. It can be enjoyed by anyone, regardless of their level of experience. When it comes to surfing, waves are one of the most important factors.
Waves are the patterns that make up the surface of the water and they determine how much fun you will have riding a wave. So how are waves measured surfing? In order to measure waves, you first need to understand how they are created.
In this article, the author James Nedock will guide you approaches to measuring waves. Now let’s start exploring!

How are waves measured surfing – Approaches to measuring waves
How are waves measured surfing?

How are waves measured surfing?
A surfboard, a ruler or meterstick, and a helicopter or balloon are needed to measure waves. Here’s how to do it:
- Draw a line on the bottom of your surfboard at the halfway point between your feet. This is your reference line (or base line).
- Check the height of the wave at each end of your reference line. Record the highest and lowest points.
- Repeat Step 2 for each side of your surfboard.
- Compute the average wave height at either end of your reference line by adding the greatest and lowest values from Steps 2 and 3, dividing by 2, or multiplying by 100 if using metric measurements. This is your wave height measurement.
- Compare your wave height measurement to the wave height values recorded at each end of your reference line. If the two measurements differ by more than 3 inches (7.62 cm), you’ve got a big wave. If the difference is less than 3 inches (7.62 cm), you’re surfing on small waves.
- Use your aerial perspective to measure the length of each wave at each end of your reference line. Record the longest and shortest waves.
- Compare your wave length measurements to the wave length values recorded at each end of your reference line. If the two measurements differ by more than 1 foot (30.48 cm), you’ve got a big wave. If the difference is less than 1 foot (30.48 cm), you’re surfing on small waves.
- Use your aerial perspective to measure the amplitude of each wave at each end of your reference line.
Causes of waves

Causes of waves
Surfers’ waves in Hawaii come from storms hundreds of miles away. Storm-driven surf is frequently too windy. Hurricanes, cyclones, and polar lows generate long-distance waves.
Storm swell is affected by the fetch, velocity, and duration of wind impacting ocean water. Winds (velocity) across an area (fetch) cause a ripple effect. This ripple effect resembles tossing a pebble into water.
The ripple may travel thousands of kilometers unimpeded. Breaking waves arise when water energy meets shallow rock, coral, sandbars, or river mouths. The wave reveals itself when ocean energy meets shallow land and local circumstances.
Winds, tides, currents, storms, ocean bottom geology, and shorelines are local circumstances. Locally strong winds spoil most nice swells. Local storms typically pollute water with land runoff.
The size of waves
There are a few factors that contribute to the size of waves:
- The wind speed and direction.
- The shape of the coastline.
- The position of the sun and moon.
- The water temperature.
The duration of waves
The height of a wave is determined by the wind speed anddirection, while the duration of a wave is determined by the water temperature.
Approaches to measuring waves

Approaches to measuring waves
The Hawaiian scale and the Bascom method
The Bascom Method, created by Willard Newell Bascom, is known for its ease and fairness. Many neglect how high an estimate it usually is! Eyes aligned with that wave crest and vertically along its journey from commencement to average sea level allow one to see the beach.
The Californians were renowned for contouring their waves from the rear, reducing their assessed height to a fraction. The Hawaiian Wave Scale exploited this mentality and gained popularity among fans of big wave surfing. It was fascinatingly thrilling to underestimate the size of an ocean swell!
Despite its advantages, the Hawaiian Wave Scale does have some setbacks:
- It is hard to figure out how big small waves are.
- From the beach, you can’t be sure.
- It depends on emotional factors such as courage.
- It doesn’t take into account the whole wave face that surfers ride.
- It doesn’t work for waves like Teahupoo that are big and heavy but don’t have a big back.
- The balanced and logical concept of surfable wave face is used to measure waves.
The technique of the surfable wave face
Surfable Wave Face Theory says that the lowest point of a surfable wave face is 2/3rds of the Bascom Method. From this point, surfers should plan their lines and techniques.
Using the Bascom Technique, a two-meter wave (6.5-foot) would be equal to a one-meter (3.2-foot) wave on the Hawaiian Scale and a 1.3-meter swell from Surfable Wave Face.
It looks like the Surfable Wave Face technique makes a wave measuring system for professional surfing that is known all over the world.
Traditional methods for wave measurement
People usually use their bodies as a measuring stick to figure out how high a wave is. In this case, terms like “head height,” “chest height,” and “waist height” are used to describe Wave Heights. This approach has its limitations, as the body can only be used to measure waves from a stationary perspective.
Despite its limitations, this measurement system is invaluable as a reference point for those who engage in surfing. By using the body as a reference, each individual has a unique height that may not correspond to an absolute value, but it still provides valuable information!
Using marine wave sensors
Marine sensors are instruments that are put on buoys that float in strategic places in the ocean. They let us measure the height and direction of waves very accurately. This approach is useful for measuring far waves because it separates data from waves further out to sea from shore measurements.
Marine Sensors: Recent Advances and Challenges
Source: https://www.researchgate.net/
Wave size table
Face height | Hawaiian Scale | Rest of World | Relative | Photo |
---|---|---|---|---|
3ft/1m | 1-2ft | 2ft | Waist-high | ![]() |
5ft/1.5m | 2-3ft | 3ft | Shoulder-high | ![]() |
8ft/2.5m | 4ft | 4-5ft | Overhead | ![]() |
10ft/3m | 5ft | 6ft | 4ft Overhead | ![]() |
12ft/4m | 6ft | 8ft | Double overhead | ![]() |
16ft/5m | 8ft | 10-12ft | Triple overhead | ![]() |
20ft/7m + | 10ft | 15ft | Huge!! | ![]() |
FAQs How are waves measured surfing
What size is a 2-foot wave?
A 3-foot wave is about 6 feet high, or 1.8 meters. A 2-foot wave is 4 feet high, or 1.2 meters, and an 8- to 10-foot peak is about three times as tall as that!
How tall is a 6-foot wave?
3ft = Waist-high. 4ft = Chest-high. 5ft = Head-high. 6-11ft = Overhead.
What size is a 5-foot wave?
It takes two half meters to make up a meter, or about 3.28 feet, which is equal to the height of one’s waistline. So three of these small units add up to about 60 inches, which is about the same height as an average five-foot wave from the surfboard to its crests.
How large is a one-foot wave?
By employing the centuries-old practice of calculating wave heights, a 1ft swell can be found between your ankle and knee. Based on how waves are measured in Hawaii, this level of swell is up to shoulder height compared to the surfer on it.
Conclusion
In conclusion, measuring waves in surfing is a simple process that can help you identify the size and shape of a wave, and determine how good the surf is. Our team at Guymac.co.nz hopes this article provide you many useful information and thanks for reading!