Tuesday, February 21, 2006

Interesting. Impressive.

I was looking at the forecasts last night and was unable to feel sufficiently confident to give a view on the proper routing. But one thing was clear - the uncertainty would lead to hard choices for the boats currently fighting out leg 4 of the Volvo Ocean Race. And the morning's position table certainly was interesting, with ABN ONE dropping from first to last.

A quick look on Virtual Spectator and it was clear the navigators had a rapid change of heart, with a dash south as in the figure above. What was really impressive is how Black Betty showed her speed and caught up Pirates. That must give Moose and the guys a lot of confidence to re-write their tactics on the fly and trust the boat to see them through.

As to where now, thats even more interesting. There are a host of lows coming in from all directions. One from the tropics, one from NZ and one from the deep south, as can be seen in the forecast from www.stormsurf.com for 2 days out:

The question is - where will the fleet be? Ok, so I have no routing software just half an envelope, and old biro and a calculator, but here goes. As in the previous post suggested, the VO70s can do about 7 - 8 degrees of latitude in 24 hours. This was ok when they were heading south, but now they are mostly heading east, so at 50S that's a factor of 0.642 or about 11 - 12 degrees of longitude per day.

At the moment they are at around 165W so this time tomorrow it will about 154W and the day after at 143W. It might be a bit less to include a bit of N/S movement eg to get to the ice gate between 148W and 143W at 48S.

So if you look at the figure above you can see the most important low is the one coming up from the Antartic, hence the dash for more wind in the south.

After that, well - again- its interesting......

Graphics from Virtual Spectator and www.stormsurf.com

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