Controlling a Beast

Going south, going south, and I just finished my turn at the wheel. Warm, sunny, 21 knots of breeze with long, rolling waves and we are making 16 knots on an upwind reach. The Volvo 70 is an animal in these conditions, and there is power to burn. You feel like you are controlling a beast. It's a great feeling.

Questions came in about our trajectory to Cape Town, and I understand if it's puzzling.

You might wonder why we are 60 miles off the coast of South America after leaving Europe for South Africa. Why are we on the "wrong" side of the South Atlantic?

I could ask myself the same question as I look at our Velocity Made on Course (the component/vector of our overall speed that is taking us towards Cape Town) and I see 1.2 knots on the display. Geez. We're going 16 knots through the water, yielding 1.2 knots toward the finish, with 3300 miles to go? Why not just stop in Rio for a burger? (Freshly ground sirloin cooked medium with cheddar cheese, avocado, tomato, grilled onions and a soft toasted sesame seed bun, basket of fries, hot fudge mint malt . . .

Sorry, where was I?

Well, the answer is, we're on this route because of the South Atlantic High Pressure Zone. It's in the way, between us and Cape Town. There's little or no wind at the center of the High, so it's faster to sail around it than through it. We're out here for another 12 days, probably, with our familiar three varieties of freeze-dried feasts and zero remaining spoons.

The High, in general, hangs out between South America and Africa at about 20 degrees South Latitude. Straightlining toward Cape Town, we'd sail into the High and slow down big time. And when we finally broke out on the eastern side of the High we would be faced with gale force headwinds for the last several hundred miles to the finish. That would be wrong twice. Thus we are chillin’ like villains over here on the sunny coast of Brazil. Our winds here are the easterly trades that flow across the top of the High, making our assault south very quick.

Once we get down to about 25 or 30 degrees South Latitude we will turn and burn to Cape Town. (We are currently at 9 S, Rio is at 23 S and Cape Town is at 35 S, with each degree of latitude being 60 miles.) It is reasonable to hope to ride a southern ocean low pressure system after we turn. The weather patterns along that late portion of the route are perfect for breaking 24-hour records. We should be able to stack up a few 500+ mile days.

Here's a screen shot from Expedition, my routing software, showing our expected path (red line) based on the 10-day GFS model and a snap shot of the weather model forecast for Oct 29th. The green dot in the middle of the screen along the red path is where we should be on the 29th. The blue lines represent MSL pressure contours. To the north of the red line is the South Atlantic High. To the southwest of Cape Town is the low pressure system we aim to latch onto.

Gives me itchy fingers. Click for the large view. Matt out