a. Spilling, Surging, Plunging: The Science of Breaking Waves
b. The Basics of Fin Acceleration in the Ocean
c. Buffalo: By Dr. Hal Handley
d. Ode to the Ocean
e. Creation Through Movement
Creation Through Movement
“Some people create with words or with music or with a brush and paints. I like to make something beautiful when I run. I like to make people stop and say, ‘I’ve never seen anyone run like that before.’ It’s more than just a race, it’s a style. It’s doing something better than anyone else. It’s being creative.” Steve Prefontaine
Bodysurfers are a throwback, guys and gals who didn’t get the memo that we should all be fighting for sponsors and pats on the back. I started out swimming with a friend and playing with the energy that unbeknownst to me was just an echo from a storm thousands of miles away. But I really started the first time I saw a guy bellyride a massive wave with ease. Coasting on the face, switching directions, all with complete control. He blew my mind. All at once I could imagine incredible things were possible with a simple pair of fins on my feet.
I became a consumer. I ate every youtube clip of Stewart or Cunningham or Wege or Panic I could find. Come Hell or High Water on repeat. Friendships with guys who loved to stick their heads in barrels spiraled into ritualistic buoy talk. When the horizon stopped bouncing we’d pine about the days when conditions were so good that our triceps throbbed and our hamburger feet needed tending.
Each swim out is another opportunity to learn something new about our craft. Mini-experiments, What happens when I kick this way while driving down the face? Can I get to the bottom and hold enough speed to complete this maneuver? Other bodysurfers are an easy study, always wondering; Why’d he drop his elbow before starting the spin? And each question punctuated by the joy in everyone’s eyes. Striking the balance between letting go of my conscious mind and engaging deliberate action is endless.
From time to time we are reminded that others are watching. Changing in the lot, a surfer lets us know he had fun watching, or a tourist will ask, “How can you do that with no board?” At one time, I was the one who had the shattered expectations of what it meant to ride waves rattling around my mind. I hold that lofty expectation in the trance of each stroke. Not only am I given the chance to traverse this natural border between terrafirma and mare, but I represent a breed of amphibious humans.
The creation of a unique memory in the eye of a passerby, might connect another soul to the aquatic world we love and protect. Granted, it is a lofty expectation, but people are tractor-beamed to the Ocean. It is impossible to tell which little Bambi-eyed rugrat will divine inspiration from a human form gliding on the surface of the big blue sea and so each wave is an act of creation through movement.
-EJ
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Spilling, Surging, Plunging: The Science of Breaking Waves
Breaking waves. We fantasize about them. We chase them. We ride them. We mythologize them. But we often overlook the incredible forces that create them. Why do waves break? One allure of riding waves is the unpredictable nature of their breaking. We can study Oceanography to understand the mechanics. We can dedicate ourselves to a spot for years, knowing it’s every mood. But no two waves are exactly the same. At the same spot, during the same swell, even within the same set. There are many forces acting to move water in that beloved motion.
The energy comes from far away; thousands of miles of open Ocean. Differences in atmospheric pressure push air in an attempt to equalize. Wind transfers kinetic energy into the water forming surface gravity waves. They propagate and organize as they travel through the Ocean as swell.
The waves of energy oscillate through the water, returning each particle back to where it started. Water molecules are spun in place without traveling with the wave. But when the energy approaches shore, gentle wave motion becomes violent water motion. The energy reveals itself, modeling the breaking wave after the bottom contours or bathymetry of the beach.
The process of the wave base slowing down on the Ocean bottom is called shoaling. Long period swell energy travels deeper in the water so it shoals before shorter period swell. Because waves usually approach land from an angle, known as swell direction, one part of the wave feels bottom before the rest. Waves always bend and refract toward shallower water. This causes waves to wrap around pointbreaks and focus energy onto shallow reefs and sandbars.
According to NOAA, “Wave steepness is the ratio of wave height to wavelength and is an indicator of wave stability. When wave steepness exceeds a 1:7 ratio; the wave typically becomes unstable and begins to break.” Wavelength is the distance between wave crests. A 2 foot wave with a 16 foot wavelength has a 1:8 steepness ratio and will not break. But as the wave shoals and wavelength decreases, the ratio changes causing the wave to break.
Oceanography textbooks list definitions for three types of breaking waves. Surging breakers rush up a very steep beach without dissipating much energy in the beach layer known as swash. Some of the energy moves back to sea, often appearing as backwash. Spilling breakers move along gradually sloping bottom contours. The crest spills down the wave face.
A Plunging breaker moves toward a steep beach, the energy spinning at the bottom of the wave feels the bathymetry. The base of the wave slows down as the crest forms upward and continues to spin. The wave front becomes concave as the trough forms below and the crest thrusts forward. The spinning energy completes its cycle, forming a cherished hollow wave.
Many of the world’s best waves are dynamic combinations of these textbook principles. Pipeline spills at 2nd Reef before the ultimate plunge at 1st Reef. Because of reflection off the jetty, Wedge can be pure chaos: surging, backwashing, plunging and dumping waves coming from every angle. Point breaks often spill for multiple sections before plunging through fast, hollow sections. Beachbreaks are especially variable; constantly changing depending on tide, wind, swell direction and sand movement.
Tide changes can alter the type of waves on many beaches. Lower tides might focus the energy in shallower water, creating plunging waves. While deeper tides can create softer, spilling waves. Many of the world’s best shorebreak waves prefer higher tides that create a combination of surging and plunging breakers on steep beaches.
Local winds also impact breaking waves. Onshore wind can prematurely blow the crest over, creating a spilling wave. Offshore wind blows up the face of a wave, suspending the crest in a rainbow of spray and holding open the plunging barrel.
After their long journey through the open Ocean, waves show their true glory when shoaling and breaking onto the beach. Much of the energy is transferred kinetically into the sand or reef, some oscillates back to sea. The remaining energy is released as that familiar sound with the formation and popping of millions of bubbles.
Breaking waves have an enormous impact on the Earth. They perpetually change our coastlines through weathering, erosion and deposition. They are dangerous and destructive. They sink ships and take lives. But when we swim into a breaking wave, locking our bodies into the spinning energy, nothing is more exhilarating. Bodysurfers chase weird, bending, hollow, plunging waves. We seek the shoaling, spinning forces and strive to feel the changing steepness. All of these forces focused on the seafloor below us: truly a blessed experience!
-KS
Sources:
NOAA Glossary
SECOORA Waves Glossary
Environmental Oceanography by Tom Beer
Descriptive Physical Oceanography: An Introduction
Wind Waves at Sea, Breakers and Surf” U.S. Naval Oceanographic Office 1947
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How to Get Enough Speed
Bodysurfers are slow. In the world of wave riding, we are at a clear disadvantage. Surfers, spongers, mat’ers, and SUPers all move faster in the water. This is an objective fact. The design of these devices give the user increased flotation, which in turn reduces drag. We, dedicated watermen, wanting to be conscious of our own efforts, look to maximize the efficiency of our movements through water. We can borrow knowledge from swimming science and infuse it with our own purposes to increase proficiency in our craft.
Part 1: Kick
The first and most obvious driver of acceleration is the bodysurfer’s kick. In typical swimming, the athlete’s propulsion is approximately 80% arms and 20% legs. This ratio changes significantly when you throw a pair of fins on that same person. Given the more than doubled surface area of the fin-covered foot, we can easily tilt the conversion to 50-50. Bodysurfers should rely on their kick for other reasons as well.
We aren’t swimming in a flat pool. Bodysurfers attempt to propel themselves onto the face of a curved wave. When we use our arms we change the shape of our upper body and risk creating drag and losing sight of the wave. Beginners often use their arms for too long, taking one too many strokes into a wave.
Some people choose specific fins adjusted to their preferred kicking style. Generally, we can describe fins in terms of how much leg drive it takes to move them. The longer and stiffer fins take longer and stronger strokes to “get moving,” while the shorter and more flexible fins are quicker to move and provide less propulsion per kick. A rider’s choice of fin is often based on the size of waves they will be riding, but ultimately what we do know for certain, is that there is a direct correlation to how much energy is exerted through kicking and a bodysurfer’s acceleration. To improve your kick power you can complete workouts focusing on the specific muscles involved in swimming (listed below) or you can bodysurf more.
Upper Leg:
Gluteus Maximus (butt muscles), Abductor magnus (groin)
Lower Leg:
Quadriceps (front of upper leg muscles), Hamstrings (back of upper leg muscles), Gastrocnemius (calf muscles), Tibialis Anterior (shin muscle), Abductor Hallucius (foot muscles), Abductor Digiti Minimi (foot muscles), Flexor Digitorum Brevis (foot muscles).
Part 2: Drag Reduction
Once you have your motor running, you can shift your focus to the art of reducing drag. The amount of resistance of an object can be calculated through the following formula:
R = 1/2 DpAv^2
R is Resistance, D is the constant for the viscosity of the fluid, p is the density of the water, A is the surface area of the body traveling through the water, and v is the velocity of the body.
As you can see from the equation, the velocity is squared. This leads to an exaggerated effect of the velocity on how much resistance a body receives in the water. The velocity of a body through water is exponentially “pushed back” or resisted. With this understanding, we look at other systems for drag reduction.
The body of a dolphin is a great example of low trim. They are able to fly through the water due to evolutionary adaptations in their physiology. The dolphin’s most forward appendage is smaller than the rest of its body. The nose disrupts the water with less resistance than if the dolphin had a large, round cranium like humans. For this same reason, we see swimmers start their race in the streamline position (shown below).
In following with nature, the swimmers are pulling their body into a tight formation, maximizing the momentum from their jump into the pool. It reduces their surface area and with this in mind we take a page from the swimming coach’s book. It all starts with the forward hand in a motion I call “the reach.”
When you are in position and starting your ride down the wave’s face, a long reach with your forward hand starts a chain of physiological adjustments that all help to reduce drag. To be precise, the reach of your hand should be making contact with the surface of the ocean. Your forward shoulder will follow suit and the angle between your arm and torso will increase, pulling that section of your body into a tighter line. While your arm and shoulder are flattening toward the surface of the ocean, your lower half will be drawn upwards pulling your whole body into a more horizontal position. As we established earlier, the more horizontal we can make our bodies, the less drag we enact upon it moving through the water.
Large surf teaches us another lesson in reducing drag. What could be better than reducing your surface area? Eliminating contact with the water all together. Bodysurfers who have managed to negotiate bigger waves can attest that when they really get movin’, their body is fully planing. In this state, water is only “dragging” on the parts of the body still in the water and our maximum velocity is greatly increased.
Bodysurfing provides an experience for athletes to be lost in the movements of Ocean. For lifelong swimmers many of these technical tenets come naturally, but no one swims perfectly. There are subtle manipulations of body posture that can mean the difference between a perfect in-and-out and a trip over the falls. As each rider navigates the wide, blue ocean, we can find the techniques that serve our purposes alike. In any case, a deeper understanding of our bodily interaction with the Ocean is always a worthwhile endeavor.
-EJ
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Buffalo: by Dr. Hal Handley
Sometime in the early 1960’s, TV’s Jim McKay’s narrative on ABC’s Wide World of Sports highlighted the pageantry and excitement of many unusual and lesser-known sports. His voice rose, crested and fell with stories portraying athletes pushing their limits for the “thrill of victory or the agony of defeat”.
From 1962 to 1965, Wide World of Sports aired the annual Makaha International Surfing Championships. During one show, the long time patriarch of the Makaha Beach environs, Richard “Buffalo” Keaulana was featured bodysurfing along the sandy shore with the incredible grace and the ease of a marine mammal at play with the waves. Perhaps the image of his joy, play and practice of an ancient Polynesian sport crystallized somewhere in my brain. The interview of Buffalo covered his (still) legendary stature as a waterman and I, just a 13-year-old Junior Lifeguard, was hooked. Buffalo stored his swim fins in his refrigerator to prevent their corrosion. Why THAT hooked me? I have no idea, an indelible image seared in my young brain. For many years thereafter, I treasured my fins and fought with my mother’s macaroni and cheese casserole for the prime cold storage location.
At that point, a seed of passion grew in my life. A passion born of being knocked down wave after wave, each time jumping up and running back into the shorebreak for one more. A passion maintained by deep pockets of sand in every ear, nose, eye and shorts carried with me nearly everywhere I went. Before I ever entered high school, I had dismissed my father’s passion for baseball and found my own in the water.
I wanted to ride like Buffalo across the waves. I was only subliminally aware of his exceptional talent. “California big-wave pioneer Greg Noll once watched Keaulana bodysurf six-foot waves at Yokohama, near Makaha. ‘He looked so natural,’ Noll later recalled, ‘streaking across the waves like a seal. I actually expected him to turn and swim out to sea when he was done” [1]. So by the time I was 16, I was determined to study and bodysurf the most famous bodysurfing wave I knew: The Wedge.
By 1969, I was comfortable at Wedge. Two large swells late that summer pushed Wedge passed the 9th pole! After innumerable attempts, poundings and some success in large surf that summer, my high school friend, Bob Gove and I endeavored to visit the legendary islands and waves of Hawaii in December of 1969.
We arrived just after one of the largest swells in surf history. Fresh fables circled the island: Greg Noll at 30ft. Makaha and journalist/bodysurfer Bruce Jenkins riding a wave through his wall and across Kam Highway- on his mattress. Five days into our trip, we witnessed Makaha rise from 2-4 feet to 15-18 feet within about 6 hours.
Here we camped, concealed in the bushes. One day, a jacket I kept for evening warmth was stolen, but when word reached the local Kahuna, the jacket was returned the following day with a verbal apology. Buffalo had heard of the transgression and corrected it without even having met us. Aloha.
Somewhat intimidated and anxious to explore the North Shore, we began “camping” in the yards of unoccupied beachfront homes. After two nights, we were rousted from our sleepy hideouts by radio reports of another impending monster swell. Evacuation orders were again issued for the second time that month. We found shelter in a chance and perfectly timed encounter with one of my Newport bodysurfing friends staying at a ramshackle mountainside bungalow.
We awoke from our high perch around 2:00am to the deep rumble of big surf. As the sun rose, we saw mountains of water, waves the size of high-rise buildings, towering and tumbling to the shore. My only estimation of size came by counting a full, one thousand one, one thousand two…five seconds from the pitch of the lip to its impact. No waves since have matched that view. Those last few days on the North Shore molded confidence into a cautious understanding of bigger surf.
As we prepared for home on our last evening, we were invited by surfer Mike Purpus and friends for a beach cookout of fresh parrot fish stuffed with corned beef hash. Bob and I had lived on shave ice, almond cookies and the odd can of Spaghetti-O’s, so this was our departure luau. We settled around a small fire when a burly local swam to shore with his days catch.
The diver was clearly a local waterman and touted “beachboy” from Waikiki. He welcomed us to share in his catch and we talked story around the fire. When I learned that this man was the Hawaiian surfing legend, Buffalo Keaulana, my adventure was complete. To Buffalo, we were two forgettable grommets among many. Upon us, he bestowed a spirit of aloha which instilled a lifelong memory whose spirit remains the same even while time erases the details. I have not spoken with Buffalo since that day, but I do owe him a debt of gratitude. His aloha launched me into many years of joy and sporting passion.
– Hal Handley, Jr.. PhD
[1] Encyclopedia of Surfing. Richard “Buffalo” Keaulana.
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Ode to the Ocean
Giant playground. Massive graveyard.
Lore and mythology. Heroes and demons.
Kanaloa, Neptune, Poseidon and Amphitrite
Hydra, The Kraken and Jaws
It’s mystery inspires fear.
The immensity encourages exploration.
The Ocean.
Absorbs red light, leaving behind…
The Deep Blue Sea.
Salt washed from rocks, flows to the sea.
97% of Earth’s water is saltwater.
The Ocean covers 72% of Earth’s surface.
Influencing everything.
Shaping coastlines. Every wave, every tide change.
Eroding land. Moving sediments.
Climate engine.
The Ocean soaks up solar energy and transports it.
Driving the atmosphere.
The Ocean absorbs wind energy.
Fetch makes swell.
Swell makes waves.
The Ocean is the medium, the wind is the force.
Our joy is the result.
Incredible marine biodiversity.
From vibrant reefs to the strange depths.
Astounding creatures abound.
Beautiful, vital and endangered ecosystems.
Demanding our respect and care.
Our family tree goes back billions of years,
to ancestors surviving in the Sea.
Our branch of life left the Ocean. But we’re drawn back.
Deeply connected to the source.
-KS
Swell Lines 