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4/02/2022 9:39 am  #1


VMC sailing along an Expedition optimized route

Howdy --

For a long-distance race, like the PacCup, we are trying to figure out Expedition tools for using max VMC.  Our first, step is, of course, downloading GRIBs periodically and running optimized routes using accurate polars.  That gives the 'long view'.  But, there will be the inevitable wind oscillations, due to squalls and other local phenomena that are not reflected in the GRIBs, and thus not reflected in the optimum route.

Our intent was to use intermediate points along the optimum route and set them up effectively as a 'mark' in the VMC calculation sense, and then maximise VMC on the local shifts.

The question is can we set up Expedition to do this automatically?  What I mean by that is set some distance along the optimum route to pick the VMC 'mark', rather than have to enter it by hand?

I see there are variables like (from the manual)
"Optimum vmc heading
The heading to achieve optimum vmc to the current mark"

But, it is not clear whether the 'current mark' can be somehow automatically updated along the optimum route.

Hope this question is making sense to all...

Cheers,
Mark
 

 

4/02/2022 10:31 am  #2


Re: VMC sailing along an Expedition optimized route

Hello again,Go to the Results icon on the Optimize tab,
click on the Optimized Route you want to start with
The Routing Solutions window will come up and at the bottom click on ->Marks
You'll now have a Route of the same name as your optimized route.

It will likely have more detail than you want but you can play around with your Settings (to create the route in the first place) or manually adjust the Marks to get the granularity you want.

Ernie


 

 

4/02/2022 2:32 pm  #3


Re: VMC sailing along an Expedition optimized route

Be very careful with VMC. I get that it gives a number to make things easy, but the number of times I have had to train people out of using it ...

It will almost always be wrong, but it can be an interesting number to keep in mind.

 

4/03/2022 7:38 am  #4


Re: VMC sailing along an Expedition optimized route

Hi Nick and Ernie --
Thanks much for useful and intriguing responses :-).  I was intrigued by Nick's comment about being careful about using VMC.  So, I'd love to pick Nick's brain with respect to how better to deal with oscillations to the wind-field that are not reflected in the optimum course calculated by Expedition :-).  I'm willing to pay for the tutorial :-))))
Cheers,
Mark
 

     Thread Starter
 

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