Hunter 28 polars

[Yann85]

Hello,
does anybody have polars for a Hunter 28 ? I have generated some using the tool from Avalon Offshore software, but when I’m calculating routes, it often gives me speeds between 5 and 6 knots, which look to me a bit over estimated.
so if anybody has polars from Hunter (I didn’t succeed to find them) or has generated them while sailing, I’m interested.
thanks

 

[jssailem]

From my observation, even with perfect polar data, due to the dynamics of weather and the decision of an owner to not make 15 tacks and 4 jibes in a 24hr period following the mathematical model of weather and polars it may be the routing software that is generating the foul speed numbers.

One way to access this would be to try the polars you have in another routing software. I am found of LuckGrib.com.

 

[Yann85]

From my observation, even with perfect polar data, due to the dynamics of weather and the decision of an owner to not make 15 tacks and 4 jibes in a 24hr period following the mathematical model of weather and polars it may be the routing software that is generating the foul speed numbers.

One way to access this would be to try the polars you have in another routing software. I am found of LuckGrib.com.

Thanks John,
I understand what you mean, but Avalon offshore is very well ranked also.
I really think something is strange with my polars. Below are two screenshots at 2 different TWS :

 

[Davidasailor26]

Are the TWS numbers in knots? The TWS 15 plot doesn’t look too wacky to me. In a good breeze like that it shows you close to hull speed on a reach or run, and 4 kts on beat, which sounds pretty reasonable to me. The TWS 31 plot does look a little wonky on a reach. But even that one looks pretty reasonable, except for the 90 degree point, considering it’s for a very strong wind.

 

[dlochner]

The TWS 31 plot does look a little wonky on a reach

That's the boat speed during the broach.

 

[Yann85]

Are the TWS numbers in knots? The TWS 15 plot doesn’t look too wacky to me. In a good breeze like that it shows you close to hull speed on a reach or run, and 4 kts on beat, which sounds pretty reasonable to me. The TWS 31 plot does look a little wonky on a reach. But even that one looks pretty reasonable, except for the 90 degree point, considering it’s for a very strong wind.

Yes, they are in knots indeed.
I‘ve just bought the boat before the winter season and had no chance to sail on it yet. I think I’ll control the polars while sailing and eventually modify them if needed.
At least these “theoretical” polars I got from calculation using boat measurements will be a good starting point.
thanks.