Thursday, 19 July 2012

It's Showtime!

Today at 1445 PDT local favourites Chuggy, Dougy, Roscoe, Evil and the Dessert Fox depart San Francisco headed for Kaneohe in the 2075ish mile Pacific Cup sailboat race.

Boats race based on a rating system and the slower boats have been starting since Monday so they have a few days head start.  The idea is to get everyone to the finish line around the same time so that the parties are well attended.  Under normal circumstances that would mean that out team would need to grind down the early starters who might get out ahead as much as 600 miles.  This year not so much!  The present leader, at 450 miles down the track, is a doublehanded J120 who started on Monday.  They managed this by sailing radically north of the rhumb line.  There is a large cluster of boats, near the rhumb line, who are only around 250 miles out.  So the winds have been unusually light for the early starters.  And it might stay a bit light for a while today as well.

Raytech is a weather routing software onboard Warrior.  They also crosscheck/interchange Raytech with a routing software in Expedition - another program.  The weather software animates wind prediction's available every 6 hours from NOAA and downloaded onboard.  Conveniently we, at Warrior World Headquarters, also have this software so that we can second guess the racers at sea!

The software would be of little value without having a clear understanding of the boats performance characteristics in certain wind and at certain angles and these estimates are called Polar Speeds.  When the onboard computer (the box not DCB) has these two components it can calculate an optimum route that the computer estimates equals the fastest way to get that boat down a track to Hawaii.  It is almost unfair right?  Not really.  Because the program and the speed estimates contain probable error, and because the weather forecasts are - well forecast - and can change - there is enough variability that these resources are only tools against which to check an over riding strategy.

Here is what Warrior's Polar Diagram looks like:

Based on Warrior's Polar Chart and a recent NOAA weather prediction Raytech estimates a stunning sub 9 day crossing.  I always expect our crew to exceed estimates so a fast trip is in store!

Should Helen and the girl's crew reschedule their travel plans?  Stay tuned here for the blow by blow - and we hope it will by the way! 

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