How a Wave Pool Works: A Surfers Guide
Last Updated on February 21, 2024 by Matt Hapgood
Surfing is one of the World’s most popular watersports. This once traditional Hawaiian sport enjoyed by the natives of both royalty and commoners alike is now a passion for many. The fact that you are totally enveloped in nature is part of what makes surfing so addictive.
These days though, man is challenging nature’s monopoly on the waves:
Dun Duuuuun! Enter, the Wave Pool!
Opinions within the surfing community are still divided if this is truly a step in the right direction for surfing. Is it a sell-out? Are we diluting the core culture of surfing? Are we allowing any old kook to learn to rip without paying his or her dues?
Do you want to learn about wave pools and how they work? In this article, we lay down all the things you need to know about this engineering marvel. Ready? Read on!
SO, HOW DO WAVE POOLS WORK?
In the basic sense, wave pools are simply swimming pools that feature human-made waves. They can generate waves that are almost like those in the ocean in terms of strength and form.
Recently, it seems the economics of building wave pools are more viable than ever, as a result, surf pools are popping up all across the globe even in the middle of the mountains in Switzerland!
Fundamentally, wave pools generate waves through some sort of mechanical means.
Some pools use pressurized air to simulate waves. Larger pools use mechanical paddles that oscillate making ripples that resemble waves. Another popular system uses a pump that periodically sucks in and then releases the water creating ripples that grow into surfable-sized waves.
WAVE POOLS ARE NEW, RIGHT? WRONG!
Despite the futuristic concept, wave pool technology is not exactly a new idea.
The earliest design dates way back to the 19th century. Ludwig II of Bavaria had reportedly rigged one of his private lakes to create waves. In 1929, artificial waves started to make their way into indoor pools. A swimming pool in Munich, Germany, had rectangular paddles around the pool.
They used it to push the water through metal grates, creating ripples in the water. It promised “no more placid waters for bathers.”
Ten years later, a swimming pool in Wembley, London, would use hydraulic technology. But it was not until 1969 that Phil Dexter would build the first-ever surfable wave pool in Tempe, Arizona.
WHAT ARE THE DIFFERENT TYPES OF WAVE POOL?
There are several different wave pool technologies out there. We’ll go through each type of pool in this article – each have their benefits and flaws, but one thing is for sure – they are all pretty darn fun!
RECREATIONAL WAVE POOLS
The first thing that springs to mind when your average Joe says wave pool, is this type – The Recreational Wave Pool. These pools were the first to be developed and opened to the public on mass in the 80’s.
The waves in these pools are pretty gentle and not really suited to surfing. Waves tend to move through the water as a small ‘swell’ and only break in the super shallow water near the edge of the pool.
Recreational wave pools are the most prominent wave pool type in the world. They’re usually found as part of a larger water park complex with other amenities like water slides.
Theme parks like the AquaAdventure Waterpark in Dubai and World Waterpark in Canada are some of the best known recreational water pools.
Typhoon Lagoon, below, is one of the OG Wave Pools.
ADAPTED WAVE POOLS
This category of wave pools is made specifically for surfing but built using traditional technologies. The common technologies used are the drop tank method and the hydraulic paddle.
The drop tank system uses the pool water itself to generate surfable waves. A tank or several tanks are placed at the far end of the pool. At the bottom of each tank is a quick-open latch that is submerged.
To make waves, the tanks are filled with pool water from a separate reservoir. When the tanks are full, the latch opens quickly draining the whole tank into the pool. The force of the falling water is what generates the waves.
The hydraulic paddle system uses large paddles connected to a hydraulic arm on one end and a hinge on the other. The paddles generate waves when the arm moves the paddles back and forth.
The floor of the pool has a steep incline near the paddles that makes the waves rise in height. The paddles can generate consistent and consecutive waves, unlike drop tanks which normally have a long lag time between waves due to the fact that the tanks have to fill up with water again.
PNEUMATIC WAVE POOLS
With pneumatic technology, it is possible to create super-impressive, surfable waves. In a pneumatic system, watertight concrete chambers with air blowers are built at the end of the pool. When these blowers vent the air out, it pushes the water inside the chambers, down and out to generate waves. This system allows the replication of different patterns of waves, some for beginners, and some for more advanced surfers.
But aside from its undeniable wave-generating capabilities, the pneumatic approach also means longevity. None of the parts would be underwater, taking away any chance of corrosion. It also means minimal maintenance cost because the pool no longer needs draining.
The staff has easy access to the system in case of a possible repair. Pneumatic systems even have standardized machine parts that make finding replacements easy. Apart from that, its multiple-chamber feature lets the system operate even with one chamber down. This makes maintenance and repair possible without shutting down the whole operation.
PLOUGH WAVE POOLS
Another supremo when it comes to wave pool technology is the plow method. Some of the big names in surf parks rely on the plow method to generate high-quality, leg-burning rides.
The mechanism consists of a hydrofoil powered by a drive system. The hydrofoil normally has a galvanized steel blade or wing like that of an airplane. It creates super-powerful waves by moving along the length of a linear track located at the center or the side of the pool.
The blades, and therefore the waves, tend to run at an average speed of between 4.5 – 7.5 meters per second.
Check this awesome clip of Casey Neistat at the Kelly Slater Wave Co below, which uses this plow style technology.
In a similar way to snow and farmyard plows, the angle and the shape of the plow push the water accordingly.
Because the plow is a fixed shape, it can create perfect waves every time – of course, this is according to the wind conditions on a particular day. This plow technology means the waves are super consistent and predictable each time.
As the plow moves, a significant amount of water is displaced from its hull. The displacement produces a large wake that then forms into waves. Adjusting the plow or foil angle and speed will create waves of different sizes and shapes.
A surfer can ride on one wave in an average of 45-60 seconds with a 4-minute interval between each wave. The waves reach a height of about 6 feet while running 10-20 miles per hour.
After completing one run, the plow will return in the opposite direction to make a similar wave but in reverse – So, one way the plow will make a right-hander, and then moving in the other direction it will create a left-hander.
LADIES AND GENTLEMEN, I GIVE YOU THE MAD MAX WAVEPOOL
The third type of wave pool technology is
THE PLUNGER WAVE POOL
This colossal device can produce waves in 360 degrees, allowing for multiple ‘surf spots’ to be ridden at the same time. Check it out below! EPIC!
The technology works by using a large, heavy plunger right in the middle of the lake. Pressurized air, lifts the giant doughnut-shaped plunger a few meters upwards (whilst maintaining contact with the surface of the water).
The plunger is then dropped downwards creating concentric waves which move outwards across the pool. The plunger’s shape ensures the waves that are created are really ‘natural’ and very much like ocean waves.
The fact that the wave generation mechanism is situated in the center of the pool allows designers to pack in as many artificial reefs around the system as they can. The reefs then help shape different types of waves from rippable beach-break style waves to heavy slabbing reef breaks.
Coupled with the fact it looks like some crazy machine from Mad Max, it allows a huge variety of waves to be created, as well as catering to a really wide range of surfing ability too. Double thumbs up from me!
WHERE IS THE KELLY SLATER WAVE POOL?
OK, so we’ve talked about the different technology and mentioned the Kelly wave pool, but I want to give a bit more information on this true feat of engineering. Nothing even came close before the Surf Ranch was built, and maybe nothing will in the future (we’ll have to wait and see).
The project was 10 long years in the making, a shed tonne of money (over 30 million bucks!), and a lot of faith in multiple people to make the job come to life.
The pool itself is located in Leemore, California about a 4-hour drive from LA, and about the same from San Francisco. It’s basically out in the middle of nowhere, built in an old waterski lake.
Do yourself a favor and relive the moment the wave was brought to the World.
One word, AMAZING!
It’s funny that in the surf World when this clip was released, it was the ONLY thing surfers were talking about. Some say Kelly broke the internet with that clip! Still gives me chicken skin today. Best man-made surfing wave in the World? For sure!
Another piece of trivia you may not know is that the day before that first wave was ridden at the Surf Ranch, Kelly flew in from Fiji – not your average preparation for a World First. Can you imagine the pressure when he took that first wave?
Another cool clip is below. Todd Glaser (the only photographer taking stills) describes that momentous day.
SURFING EVENTS IN A WAVE POOL?
As wave pools become more and more popular, the opportunity to create that elusive ‘level playing field’ in surfing finally exists. Having said that, way back in 1985, the very first wave pool surfing contest was held – It went ahead in the great surf mecca that is Allentown, Pennsylvania (yeah, 2 hours drive from the ocean, look it up).
Australian Tom Carroll came out as the winner and received the title, which I am sure he will never forget, “Inland Surfing World Champion.”
Unfortunately, the event was pretty lackluster and didn’t really garner much attention from the wider surfing community. Fast forward to May 2018, the World Surf League picked up the idea of inland surf contests once more.
The Kelly Slater Surf Ranch in Lemoore, California, hosted the Founder’s Cup. It became the first-ever World Surf League event held at a wave pool.
Months later, the same surf pool hosted the inaugural Freshwater Pro. This move caused some eyebrow-raising in the surfing community. Surf fans questioned the league’s choice of man-made waves over real ones.
Renowned professional surfer and owner of Surf Ranch, Kelly Slater, defended the existence of wave pools. He clarified that they could never replace nature’s best, but rather “supplement it.” So far, there have been two editions of the Freshwater Pro.
Brazilian surfer Gabriel Medina bagged the men’s championship for two consecutive years. Carissa Moore and Lakey Peterson secured the top spot for women’s in 2018 and 2019, respectively.
Despite the initial backlash, WSL showed interest in wave pool technology and its potential in the competitive scene. Upon publishing its 2020 schedule, Surf Ranch made a comeback in the lineup. This time it was the Michelob ULTRA Pure Gold Freshwater Pro. Hawaii’s Coco Ho and Brazil’s Filipe Toledo took home top honors this time.
The win was owing to Toledo’s near-perfect wave being the highest-scoring wave of the day. This duo also competed in the mixed tag-team event against 16 phenomenal surfers. They were able to beat the likes of Alyssa Spencer, Kolohe Andino, Sage Erickson, and even the 11-time WSL champion, Kelly Slater himself.
The WSL weren’t the only ones to drink the Wave Pool Kool-Aid. In 2018, an aerial surfing contest took place at the BSR Wave Park in Waco, Texas. The inaugural Stab High was a contest that strayed away from the usual competitive format. More like a freestyle snowboard event, the comp focused more on aerials and freestyle surfing.
The consistent air sections at Waco’s wave pool were the perfect recipe for radical futuristic surfing. The surfers invited consisted of aerial specialists and not the run-of-the-mill WCT surfers. Emerging victorious at the end of the inaugural Stab High contest was Noa Deane, with Eithan Osborne bringing home $25,000 for the highest air of the event.
It looks as though wave pools are now here to stay, partially due to the fact they are more commercially viable than ever.
Couple this with the Worlds top pro surfers using them as a training facility, the sport of surfing as we know it is at a tipping point into something seriously mainstream and maybe about to split into two directions – Are you a pool surfer or an ocean surfer?
I’m not sure I agree with Kelly Slater when he says this shift to wave pools will “democratize surfing” – to hire the Kelly Slater Wave Pool for a day apparently costs, wait for it… between $35,000 – $50,000!
SURFING IN THE OLYMPIC GAMES?
Now, people ask, will wave pools have a future in the Olympics? Surfing has indeed been slated to make its debut at the 2020 (well, 2021) Olympics. In preparation, Japan built the Shizunami Surf Stadium.
Unfortunately (for the investors anyway) it doesn’t look like wave pools will be taking an active role in the Olympic event. Kimifumi Imoto, director of the Nippon Surfing Association, had envisioned wave pools as “a key part of optimal training” giving the Japanese team a base to train and perfect their skills.
As per the World Surf League events, the Olympic event will use the same format. Surfers will have an allotted time to catch two ‘scoring rides’ marked out of 10 (so a two-wave total marked out of 20). Each heat will comprise four surfers, and at the end of the heat, the top two surfers will progress onto the next round.
Personally, I think the format is a little clunky for non-surfers to grasp. Combining this with the fact that event organizers are at the mercy of the ocean in terms of conditions, it might be a difficult concept for the mainstream public to get excited about.
Time will tell, but I think a wave pool event could have been a better direction to really get the attention of the World and really shine the spotlight on surfing.
FINAL THOUGHTS
Wave pool technology has come a looooong way in recent years. With wave pools now able to cater to beginner surfers and seasoned pros alike, I think they are only going to become more and more popular with time. I also think they won’t eliminate regular surfing, or even reduce the crowds in the ocean like some pundits have suggested.
The restrictions on travel for many surfers over the past year or so, have resulted in a boom for places like The Wave in Bristol, UK, and URBNSURF, Melbourne Australia. Instead of booking that airline ticket, dropping $100 on a day at a wave pool seems like a pretty sweet idea at the moment.
Check this final clip of URBNSURF below and get stoked on the idea of getting tubed in the pool! Yewww!
