Thursday, 23 February 2012

Human intuition trumps the computer in erratic conditions

Computer navigation model showing the Easterly option
Only four days into the leg and the fickle hand of Mother Nature in the shape of  unpredictable weather conditions has forced the teams to consider rationing their provisions.

On PUMA, MCM Amory Ross said that predictions of a longer leg meant careful monitoring of food and vital supplies had already begun.

“Our predicted 18-day leg has turned into a 20-day one, maybe even 21 or 22; it is hard to know as the models keep changing,” Ross wrote.

Recycled meals
“We’ve started setting food aside and are mindful of our valuable resources like propane and toilet paper. Yesterday’s lunch was recycled, and, with a little hot water, became yesterday’s dinner, too.”

Gonzalo Infante, Volvo Ocean Race’s chief meteorologist, reports: “The wind is forecast to go so light that, with the waves as big as they are, we could see the boats going backwards.”

All the teams rely entirely on the weather data sent to them every three hours using FB150. They feed the GRIB files into their navigational software and then run several hypothetical predictions with different outcomes to ascertain their options.

Down to experience
It’s then down to the navigators and skippers to make the call on which way to go tactically.

The trick is to use human intuition and experience and not just blindly follow what the computer says.

The computer models are only as good as the data imported. When the conditions are so erratic and changeable, it’s hard to draw too many conclusions.

Heading east
Yesterday, Abu Dhabi Ocean Racing skipper Ian Walker said: “I wish I could tell you what the next few days hold.

“The weather files haven’t really matched up with the actual weather we’ve had since the start really, so we’re not really paying too much attention to them.

“We’re just trying to get east as fast as we can.”

Aggressive sea
The fleet has now come through the Luzon Straits and is making progress east. They are all still complaining about the uncomfortable upwind sailing and the aggressive sea state.

Camper and Groupama are the furthest east, sailing more miles east in the hope they will get a better sailing angle south when they finally get into the trade winds.

 Mark Covell

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