Aeolian Rhapsody

The past week has been defined by unusually strong autumn winds. The Western Cape has predominant south-easterly winds during late spring and summer, and north-westerlies during autumn and winter. However, the Aeolian Gods had different ideas this April, and we experienced a few days of gale force winds diving out of the southeast horizon and blowing everything hither and yon. Waterfront Charters don’t mind wind; after all, it powers two of our beautiful yachts silently and effortlessly and pollution free. But sometimes we can have too much of a good thing – it’s great to be ploughing through gentle Atlantic swells with a breeze billowing the mains’l and jib; it’s entirely different to be carving through white water under a storm sail, with guests clinging to masts, stanchions, the skipper, each other, with the whites of their eyes showing. We’ve said it before and it bears repeating: safety is and always will be Waterfront Charters first consideration. Out boats can handle the weather, but our cruises are designed to be pleasurable affairs, not some form of Fear Factor challenge.

Wind is something every human on the planet will experience regularly, but it’s unlikely that too many people outside of science and meteorology ever give its causes a second thought. In simple (very simple) terms, it’s a flow of gas from a high-pressure to a low-pressure zone. Which is why barometric pressure has always been an important part of weather forecasting. In actuality, there are many winds, ranging from the transfer of gases on earth to the solar winds that streams from the sun and stars – flows of a plasma consisting of mostly electrons, protons and alpha particles, at speeds ranging from 500 to 750 km per second. As wind powers our yachts here on earth, it’s a possibility that one-day starships will be driven across space by these solar winds. (They would need mighty sails, mind you: hundreds of square kilometres in diameter. But no need for any fuel for the mind-boggling distances they will have to cover.) The fastest wind ever recorded is coming from the accretion disc of the IGR J17091-3624 black hole. Its speed is 32 000 000 kph which is 3% of the speed of light. No matter where we go in space, and how we do it, it’s going to take a lot of time…

Winds also blow on all the other planets in our solar system: when you were holding on to your hat this week, it’s unlikely you spared a thought for Venusians, with their constant 300 kph winds, or the irritated denizens of Neptune who have to commute in winds of up to 1100 kph. Waterfront Charters won’t be opening branches there anytime soon.

“Nature, with equal mind, Sees all her sons at play

Sees man control the wind, The wind sweep man away.”

Matthew Arnold: Empedocles on Etna

But wind has held a special place in the history of Earth. It has carved the bulk of the planets topographical features; it has powered ships and pumps and dispersed seeds. It has altered the course of wars and has kept aeroplanes flying for the past century or so. It is a continual source of recreation: from sailing to windsurfing, kite flying to hang-gliding and hot air ballooning. Not to mention surfing, that Cape Town staple: wind not only creates the swells in mid-ocean but holds them up as they reach the shore, so surfers can ride the breakers. The eagle’s claw shape of our peninsula means that there is always an offshore wind somewhere: if the Atlantic is flattened out, the False Bay side will have glassy tubes and vice versa.

Wind has been used as a power source for centuries, but with the discovery of electricity it is coming into its own; the windmills of the past are now huge propeller-powered turbines that grind out the watts as the wind rotates the blades. The Gansu Wind Farm in the Western Gansu Province of China has an estimated 5000 turbines operating; they are aiming at producing 20 GW of power by next year, and this is without burning a single molecule of fossil fuel. (To put this in perspective, Koeberg, our nuclear power station, has a maximum output of 930 MW, less than a fifth of Gansu in terms of power produced.) Wind is not called a ‘renewable energy source’ for nothing: wind turbines have the lowest global warming potential per unit of electrical energy generated

But there are always downsides to everything, and the destructive force of wind is well documented. The Beaufort Scale lists 17 levels of wind speeds, measured in ten-minute sustained intervals. They range from number one: <2 kph (calm) through Cape Wind levels at number eight, 63-74 kph (fresh gale) to number seventeen: >222 kph (super cyclonic storm.) We can’t really complain, now can we? Our Cape Doctor may puff and blow, but in the bigger picture, we experience nothing more than the odd annoying coastal gale.

Take advantage of the gentler side of the winds: feel the breeze in your hair aboard one of our wonderful cruises. Whether you are being powered by wind or motor, nothing beats the sights, feel sounds and bracing ozone smells of an offshore adventure. All hands aloft: we’re raising sail!