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The Doldrums - Sailing's Dead Zone
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The Volvo Ocean Race 2001-2002
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The Volvo Ocean Race yachts are marvels of modern engineering, but, alas, they share a common flaw. They have to have wind. Granted, wind isn’t normally in short supply on the open ocean—until you hit the doldrums.

For centuries mariners have feared this equatorial region for its tendency toward sailor-stopping calms. The first leg of the race runs right through it, and what happens there could conceivably determine the victor.

“It’s incredibly frustrating. It's the worst thing,” says Kevin Shoebridge, captain for the Tyco team, a competitor in the 2001-02 race, of being stymied by dead wind in the doldrums.

The region is also prone to violent weather shifts, and Shoebridge says he’s seen calm winds turn to 30-knot gales in a matter of minutes. At other times he’s sailed through without noticing a thing.

Cooking Up Trouble

The trouble starts with the sun’s concentrated pounding at the Equator, which bakes air near the ocean’s surface, making it lighter and causing it to rise. Sailors are picky about wanting their air movement to be generally horizontal—rising air offers little wind for the sails and can stop boats dead.

While heating the air, the sun also cooks ocean waters, soaking the rising air with evaporated water, which can result in violent storms. “There was one particular instance where it was just a huge black wall of cloud from one horizon to the other,” says Shoebridge.

To top off the doldrums’ troublemaking, the sun’s beating does a bang-up job of heating Volvo racers as well, who can find their bunks well over 100F (38C).

Next: “It’s always a nice bit of fun to pick on the young guy.” >>

 
Equatorial air, being generally hot, and therefore light, rises high into the atmosphere and toward the Poles. As the hot air rises, cooler, denser air rushes diagonally toward the Equator from about 30° north and 30° south, creating the trade winds.
 
The convergence of the northeast and southeast trade winds around the Equator results in a shifting belt of light winds and unpredictable weather known as the doldrums.