If you read surf reports (if not, try one out: Corpus Christi surf report) you might wonder what the heights mean. What’s a head high wave? Exactly how tall is that? And is that the height from the bottom of the ocean? What’s ankle high? Why would they even report an ankle high wave? If you’re wondering, you’ve come to the right place.

How Waves are Measured

Wave height on surf reports is measured simply by looking at the water and guesstimating the height of the wave as compared to the average person. The height is also guesstimated from the top of the water. For example, if you were to walk out in the water and it was waist high, and then the waves were so high that if you stood on the water (like, if you were standing on a surfboard) they would reach the top of your head, that would be head high.

Head High Waves

Most people would call those 8 ft waves. This is because if the water is up to your waist when you walk out in the water, that’s about 3 feet of water, give or take a foot. For the waves to reach your head while you stood on the water, they’d have to be about 5 feet high on top of the first 3 feet. That’s 8 feet, but to surfers, those are 5 foot waves. They would simply be called “head high waves.” Or: “Hey man, how’s the surf today?” “It’s head high! Get on it!”

Waist High Waves

Waist high waves are waves that would reach your waist if you were standing on the water. People who don’t surf would probably call them 6 foot waves.

Chest High Waves

Chest high means the waves would come up to your chest if you stood on top of the water.

Knee High Waves

Then there are knee high waves, which, of course, are waves that would come up to your knees if you were standing on the water. These could be decent for long boarding.

Ankle High Waves

Ankle high waves aren’t really good for anything but boogie boarding (which is fun!). On a day when the waves are ankle high, the surf report might say something like: Barelling ankle high surf, great waves for GI Joe!

Other Wave Heights

A lot of the time you’ll find that the surf report says a combination of these, such as:

• Knee to waist high
• Waist to chest high
• Chest to head high
• Head high and over

People come in all shapes and sizes, so these measurements are just really good guesses. The surf report is meant to give you a good idea of what to expect at the beach.

What to Expect from a Surf Report

Aside from telling you how high the waves are, the surf report should also tell you:

• How strong the current is and what direction it’s going
• How powerful the waves are
• The water temperature
• Anything important going on at sea, such as a hurricane on the way
• What to expect for waves for the rest of the day and the rest of the week and weekend
• Any news of jellyfish, sharks, or anything else related to your local surf spots
• A good surf report will even keep you informed of upcoming surf competitions
• The best surf reports are written before 8am. There really aren’t enough of these around.

Writing the Surf Report

So who walks out there on top of the water to find out how high the waves are? No one! The surf report is usually written by the surf shop owner, who drives down the beach before work, sipping his coffee. Or by the same guy after a 6:30am surf session known as dawn patrol. The surf report is usually just eye-balled. And sometimes they’re not what you would agree with. I’ve gone out to the beach on days when the surf report said the surf wasn’t very good, and ended up having a blast on my board.

If you’re not sure the surf report is correct or if you don’t have access to one, it never hurts to get wet and find out for yourself. If in doubt, paddle out!