“That’s the whole thing, to get inside the barrel wave,” says Elijah Mack, surfer, barber, and Portlander. “That’s the surfer’s ultimate goal. When you’re in the tube, everything else stops. It’s the only time I’ve felt truly Zen."
Here’s the catch: Mack’s talking about surfing on rivers, not oceans. And he says that his collaborative work with a Colorado-based engineering firm created a design for a barrel wave, “the most perfect wave possible,” on a river.
By his estimation, Mack has surfed more than 200 river waves on more than three continents during a long —some might say legendary—river surfing career. Riverbreak magazine describes him as “one of the greatest pioneers in the history of the sport.” Mack sidelined his river surfing pursuits for a decade to focus on his hair career (devoted readers may remember Portland Monthly’s article about Mack’s downtown barbershop). But as the godfather of river surfing, he couldn’t resist the waves for too long.
Five years ago, Mack watched a Youtube video of a man named Benjamin Nielsen surfing a wave popular among the river surfing community, the Lunch Counter wave on the Snake River. But Nielsen doesn’t just surf river waves – he also designs them. Nielsen currently works for McLaughlin Whitewater Design Group, a hydraulics engineering firm known for an innovative advancement in wave technology called the “Wave Shaper” that was implemented at the Boise River Park.
“Boise was where manmade waves really changed,” Nielsen says. “Creating reliable waves is one of the biggest challenges for wave design because these rivers are so dynamic. And if you don’t have waves, you don’t have river surfers, and you don’t have a river surfing community.”
Mack and Nielsen became fast friends, talking extensively on the phone about the future of river surfing, which the two both believe will be brighter once designs for reliable river waves become more widespread. The two come from different professional worlds: Mack runs a bustling barbershop while Nielsen is a professional hydraulics engineer and alum of Cal Poly San Luis Obispo’s rigorous Civil Engineering program.
Yet when McLaughlin Whitewater Design Group hired Mack’s river surfing consulting firm FresH20 to collaborate with Nielsen on a project for Denver’s South Platte River, the two formed a mutually beneficial partnership: “I’m an engineer who surfs, and he’s a surfer with a lot of creativity,” Nielsen says. “I can say ‘oh that’s cool, let’s try it,’ or ‘oh that’s a little too wild’ - tweak this, tweak that.”
The project goal was to create a low-flow wave for the South Platte. Nielsen constructed a scale model of the river at Colorado State’s Hydraulics Engineering Lab, and the men joined forces with CSU doctoral student Natalie Youngblood to see what they could do.
The group was trying to design a wave that would optimize the South Platte’s low water flow, but instead they stumbled upon a way to construct a barreling river wave—something that has proved challenging to engineers in the past. Though nature has produced barreling river waves, like the treacherous Tubesteak wave on Canada’s Skookumchuck Narrows, Nielsen and Mack say the river surfing community has historically been skeptical that reliable barreling waves could come from the lab. So what makes their new design different?
To answer that, Nielsen says we need to first talk about the two basic forms of river waves: sheet flow and hydraulic jump. In a sheet flow wave, the shape of the wave is entirely dependent on how fast-moving water interacts with the bottom surface of the river, meaning that an object can be placed there to create a wave. Nielsen has never heard of a naturally-occurring sheet flow wave. The hydraulic jump wave, which forms both naturally and artificially, is generally created when slow and fast water interact explosively. There are several more specific hydraulic jump formations, which interested readers can learn about in Nielsen’s article published by the river surfing magazine Riverbreak.
At CSU, Mack, Nielsen, and Youngblood created a “very specialized type of hydraulic jump,” Nielsen explains, “where the form of the barrel does depend on the manipulation of slow downstream water and fast upstream water. But this design is really about manipulating the different wave elements in all three dimensions, where some wave designs only work with two.”
The technology is still in model form (you can see the small-scale wave in action here) but Mack and Nielsen see a promising future full of those “perfect waves” in store for their sport. The design has received “a tremendous amount of positive feedback from the river surfing community,” Nielsen says, “and we’re looking for a site to place this wave.”
Or, as Mack puts it, they’re “going to change the face of river surfing.”