Wednesday, June 4, 2008

A routing dilemma - what to do now?

Today offers some particularly nice insight into some of the problems they are facing on Cirrus: Where to go - above the High or below? You can see it laid out on the Cirrugator-Demo page.

Look at the weather faxes first: The Pacific Surface Analysis (left picture) shows a High (32N/142W) with the note 'STNRY' (stationary) next to it, and the 2 day forecast (right picture) confirms stationarity for even 2 days later! The High isn't moving any time soon. If they were sailing-only, with no option for motoring (as in a race), they could go either below the High and face 10+ days of close hauled misery, or go above the High, and go comfortably but almost 2 days longer. The many colored routes in the first, topmost graph represent all the options. The second graph shows that they can go fast (red diamonds, with speeds into 8 knots!) but in misery (blue filled circles for Apparent Windangle).

Now in delivery they can take advantage of the engine and go through the center of the High as a compromise, but that would require a lot of diesel fuel. And to decide on this in the early part of the trip is also no good option; they might regret this dearly later on.

This is a situation we would like to have during the race, going the other direction, but not now. So what to do now? Stay tuned to see how Bill will decide.

Ulli

1 comment:

Dawna said...

Thank you for your detailed and quite informative insight into Cirrus' routing dilemma. And following along with the Cirrugator-Demo page was particularly educational. Looking forward to hearing a successful outcome.
Dawna