"Polars"by mfgs are ridiculous

[geoleo]

as they never take sea state into account-all are given in calm water LOL

[colemj]

Manufacture's polars are calculated ones by the designer using a software program before the boat is even built. They don't take the actual build into account, let alone how it is equipped, etc. They are generally wildly optimistic.

Actual polars, if desired, should be calculated by the individual boat owner for their particular boat in the sailing conditions typical for the area. Even highly standardized, controlled-build and equipped class racing boats do this.

Even if the manufacturers provided real, empirical polars, how would you expect them to provide polars based on sea state? The combinations of sea state are almost infinite. I fail to see why you condemn that.

Did Woods provide you with empirical polars on your specific boat in various sea states? Or are you just bashing production boats again?

Mark

[geoleo]

Your first comment reinforces my thrust--"WHy Bother with useless phony "Polars" (except to fool the buyers.)

[geoleo]

To respond to your last comment: Richard Woods does not deal in ********.

[colemj]

Your original post was a condemnation of polars not taken in various sea states - it was not about why they provide only calculated polars and how those get used. Perhaps I am too obtuse to read in the meaning of your revised post from your first post.

Every manufacturer provides the designer-calculated polars just like they provide any other design data. Even one-off and custom boats like Schionning and Gunboat provide these. Calculated polars have their use in examining the design parameters of different boats. They are not "********".

If they get used incorrectly by a potential buyer, that is not the designer's problem.

Mark

[geoleo]

SO what is the use of these "polars" except as marketing propaganda?

[geoleo]

"provide other design data" except for the all important underdeck bridgedeck clearance------

[TeddyDiver]

Originally Posted by georgetheleo

SO what is the use of these "polars" except as marketing propaganda?

Not actual fan for polars myself, but why you are so frustrated? Just ignore them..

[Bash]

Interesting. In the higher end of the racing world, polars are considered gold.

The frustration expressed by the OP may be caused in part by a misunderstanding of how polars function. The polar is not a prediction of top speed. Rather, it functions to indicate a target speed that should increase VMG. For example, the polar says that in such-and-such a breeze on such-and-such a point of sail, my target speed should be N knots in order to maximize VMG. What this means to a knowledgeable helmsperson is that the boat should be pinched up a bit if the target speed is exceeded, and footed off a bit if the target speed is not achieved.

In my experience, which is admitted limited to racing monohulls, I'm amazed at how often polars have proved true throughout a variety of conditions. The only time I've been frustrated by them is in exceptionally light air, but often this is because of tired sails, a less-that-perfect bottom, or too much weight in the boat, not because the polars have predicted the wrong target speed.

[barnakiel]

I never found them ridiculous. When you understand what they represent they are pretty clear and most often quite accurate.

If you want polars for specific sea states / wind forces / ship loads / sail choices nothing stops you from making your own (or hiring someone to make them for you).

Cheers,
b.

[Barra]

Originally Posted by Bash

Interesting. In the higher end of the racing world, polars are considered gold.

What this means to a knowledgeable helmsperson is that the boat should be pinched up a bit if the target speed is exceeded, and footed off a bit if the target speed is not achieved.

.

I reckon if the knowledgeabel helmsperson tries doing that with the L40 polars (posted by saleman on recent other post) they would end off bearing way and sailing circles trying to achive the mythical speeds on that polar!

[Bash]

Originally Posted by Barra

I reckon if the knowledgeabel helmsperson tries doing that with the L40 polars (posted by saleman on recent other post) they would end off bearing way and sailing circles trying to achive the mythical speeds on that polar!

Are you talking about this polar? Honestly, if you can't match such conservative target speeds you probably ought to give up sailing.

[Barra]

Thats the one and agree its not that aggresive and seems a pretty reasonable target on teh surface BUT the leapard rep on board and 2 experienced crew with concervatively 15 years combined experience on leopards couldnt get within cooee of that polar....

guess they better give up theie jobs on your point?

[cwyckham]

I would love to have polars for my Niagara 35. Of choose they would be for flat seas. How the heck else would you do it?

I'd love to put together a crossover chart as well

[Bash]

Originally Posted by Barra

guess they better give up theie jobs on your point?

no need to give up their jobs... just find a hobby other than sailing.

Some fellows really ought to stick to lawn bowling.