The Wonder of Cold Water Swimming

A version of this story was originally published in Sawubona magazine.


Craig Foster is an amphibian.

He spends more time in the kelp forests around Cape Town than most fur seals.

Every day of his life, rain or shine—and today, the weather could not be worse—he enters the chill waters near his house on the Cape Peninsula to study and record the marine creatures along its shore.

An award-winning anthropology filmmaker and co-founder of SeaChange, Craig believes that being cold was a regular part of the lives of our early stone age ancestors, and over time, we have evolved mental and physiological adaptations to these extreme environments. A wetsuit, he says, disrupts the body’s natural coping mechanisms in the water.

As a freediver I’m accustomed to covering myself in sticky neoprene before slipping into the ocean. But today, on the icy winter solstice, Craig has invited me to push my body to its limits; to immerse myself in the ocean environment sans wetsuit—to experience what he calls the ‘primal joy’ of skin diving.

Image by Craig Foster

Rain pummels the sea around my bobbing head.

The rest of my body, suspended beneath the swell, clenches in the cold ocean.

I take in gasps of salty air and exhale clouds of condensation that rise and disappear into the dark winter sky.

It’s a frigid day to be snorkelling off the jagged rocky coast of Cape Point wearing nothing but shorts and a dive mask, but I remind myself not to worry. The amazing thing about my body is that it will soon adapt to the cold water.

Already, the terrible razors I felt on my fingers and toes when first wading into the sea are gone. My skin is slowly taking on the temperature of the surrounding ocean, and my chest is burning warm in the cool blue.

“Deep, short breaths of air!” shouts Craig through the wind and rain.

Most mammals, including ourselves, are surprisingly well adapted for surviving in the cold. And it’s awakening these internal survival mechanisms, some scientists say, that may have positive effects on your health and well-being.

One of these adaptations is our very own built in thermal ‘wetsuit’ called brown fat—an invisible tissue that creates heat energy when activated by the cold. Once thought to only occur in newborn babies, recent studies have shown that brown fat in adults may contribute to weight loss and prevent obesity. A 2014 study, published in the journal Cell Metabolism found that 15 minutes of cold exposure can be the metabolic equivalent of an hour of exercise.

Cold water immersion also causes vasoconstriction in the body, which is when blood in our arms and legs shunts toward our core and vital organs to keep them oxygenated in extreme conditions.

Aside from keeping us warmer and safer for longer, studies have shown that this process can have numerous health benefits, such as a stronger immunity against disease, enhanced pain tolerance, and greater stress resistance. There are also anecdotal reports of people who feel happier, more focussed and energised with regular exposure to the cold.

International sports stars David Beckham, Johnny Wilkinson and Kobe Bryant, use ice baths (Cristiano Ronaldo has his own cryotherapy chamber installed in his home) to assist in speedy recovery after injuries and gruelling training sessions. The theory goes that when they get in and then out of a cold bath, their arms and legs fill up with ‘new’ blood that invigorates muscles with oxygen to help the cells function better.

Professor Tim Noakes, a sports scientist from the University of Cape Town, says that the health benefits of cold water immersion are likely, but hard to measure.

“I think this type of activity generally attracts people who are looking to be healthy,” said Noakes. “So it’s the discipline of everything; eating right, exercising and swimming that might contribute to overall health.”

Photo by Craig Foster

The weather has taken a turn for the worse.

A cold wind sweeps across the grey bay, whipping spray off the tips of waves. My body tingles, and my heart beats slowly.

“How are you doing?” asks Craig.

“I’m warm,” I reply.

I sink my head beneath the frothing water where it’s quiet.

The long bronze kelp trunks sway to and fro in the surge, and sediment swirls around like a silent cyclone. I draw a deep breath of air, and grab hold of a branch that disappears down into the murky blue.

I begin to climb.

Down, down and down I climb, into the blue abyss. The deeper I go, the quieter it gets, until I hang like an astronaut on the ocean floor. A gap of light brightens the water and all the colours come to life. Spiny red urchins carpet the floor; giant sponges hang off the rock walls, silver fish glint, jellies drift, and grey shades of anemone wave on the rocks.

I’m just 100 meters from the main coastal road that winds on to the sprawling city of Cape Town. Yet down here, in this cold swaying forest, I’m exploring an some alien world.

Photo by Craig Foster

We eventually flop out of the tide and stumble onto the rocks, drunk from gravity.

The air feels strangely warm in the cool wind.

“We were in the water for 50 minutes!” shouts Craig, as if he has just had a dip in the Bahamas.

Like most forms of ‘exercise’, it is possible to condition one’s body to better handle cold water for longer. After years of diving has enhanced Craig’s ability to thermoregulate—maintain a stable core internal temperature—and conserve heat.

We both dress in warm clothes, do a couple pushups, and then sit for a while on the rocks, my teeth chattering.

“Discomfort is all in the mind,” Craig reassures. “Sometimes, when I feel myself getting cold, I imagine a warm flame in my chest, or focus on something else, and I feel OK again.”

The sun peeks below the storm clouds like a log fire in the snow, thawing my cheeks.

I’m warmer now.

But I can already feel the pull of the deep cold blue.


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  1. Philipp Harper
    Florida, USA
    December 10, 2016, 10:20 am

    Interesting, but would have been much more so had the writer told us the temperature — air and, more important, water — on the day he was diving. Huge omission.