26 September, 2019 26 September, 2019

Where the Wind Blows

Wind, glorious wind. We love it. We hate it. It is both creator and destroyer. Both friend and foe. It is surfing’s ultimate dichotomy.

Our relationship with wind is anything
but ambivalent. It breathes life across the ocean to create the swells that become the waves we ride. We surf because of wind. We also don’t surf because of wind. Unbridled optimism at the prospect
of some solid groundswell arriving at
your local spot can quickly be tempered
by the frustrating reality that it’s often accompanied by unfavourable winds. Devil winds. Onshore winds. Gale force offshores. Nothing can affect a surfer’s mood quite like wind.  And it’s all thanks to the sun.

Cover Image – Daniel Grebe.

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© KIM BOUCHIER

There’s an African proverb that goes:
 when the roots are deep there’s no reason to fear the wind. But does your board have deep enough roots for this? That’s because the Earth is tilted on its axis, so the planet cooks unevenly in the sunlight, like a piece of boerie on the braai that you’re not paying proper attention to. The tropics get roasting hot whilst the polar caps are locked in ice.

The wind is created by the planet trying to even out the energy. How it makes waves is quite simple. Water has surface tension. Deform it slightly, and the pulling force between neighbouring water molecules will rapidly spring back again. As the wind starts to blow over the water, it creates teeny ripples called capillary waves that are hardly a millimetre high. The water’s surface tension, kinda like its own elasticity, tries to destroy them immediately by tugging them back into place.

But if the wind keeps blowing the water surface starts to roughen up with these little capillary waves. Now friction kicks in, allowing the wind to get a better grip on the surface, systematically building up the ripples to make wind chop.  Once waves grow beyond capillary size, surface tension can’t stop them. Game on! Wind chop starts to form, which can eventually grow into the swell that unloads on our shores as perfectly formed surf.

The holy trilogy of wind are its speed, duration and fetch. The harder and longer it blows, and the bigger the area it blows over in the same direction combine to create the deep ocean groundswells that make us bunk school, skip work and be delinquent in general.

Photographer: Stephan De lange

The wind is what defines a wave’s personality. Onshore and it presses down the back of the wave-making it crumbly. Offshore and it grooms the wave whilst blowing up the face. Pap? That’s a wind swell. They’re generated by local winds within a few hundred kays of the coast and are characterised by short periods and steep, choppy waves whose energy doesn’t extend very deep. Grunt? That would be a groundswell. Generated by strong winds much farther away, creating longer swell periods whose energy can extend down to around 1 000 feet deep. What makes them golden to surfers is that they are no longer affected by the wind that generated them. Unless of course, some local wind conditions mess things up.

Wind isn’t only about near and far. Land and sea breezes throw their own little dynamic into the mix. Ask any KZN surfer about how a pristine dawnie can disintegrate into onshore slop in an instant. Snooze you lose. Like it or not, wind is the primary thread woven into the fabric of our lives as surfers. It’s the most clicked icon on our desktop and app on our phone. It means everything to us. It can deliver, and it can disappoint. But remember, it’s always offshore somewhere.

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