# Polar Diagrams



## sandycohen

Does anyone know of a good resource of polar diagrams for older boats? I am trying to find one for my Pearson 32, without shelling out $300 to USSA.

Thanks!


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## Grendler

Polar for Pearson 33 below. Can't remember the source but I got about 80 of them...

TWA	6	8	10	12	14	16	20
52	4.6	5.5	6.0	6.2	6.4	6.5	6.6
60	4.9	5.8	6.3	6.5	6.6	6.7	6.8
75	5.2	6.0	6.5	6.8	7.0	7.1	7.2
90	5.4	6.2	6.7	6.9	7.1	7.3	7.5
110	5.2	6.1	6.7	7.0	7.3	7.5	7.7
120	5.0	5.9	6.5	7.0	7.3	7.6	8.0
135	4.4	5.4	6.2	6.7	7.1	7.4	8.0
150	3.7	4.7	5.5	6.2	6.6	7.0	7.7


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## Mark1948

Anything for a Catalina 27?


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## Grendler

Diagrams are from 33ft (Pearson, Contessa) up to 60ft (Centurion, Deerfoot, Swan). Sorry 

Catalina I got only 36 model:

TWA	6	8	10	12	14	16	20
52	4.9	5.8	6.3	6.6	6.8	6.9	7.0
60	5.3	6.2	6.7	6.9	7.1	7.2	7.3
75	5.6	6.5	6.9	7.3	7.5	7.6	7.7
90	5.7	6.7	7.1	7.4	7.6	7.8	8.1
110	5.6	6.6	7.1	7.5	7.8	8.1	8.4
120	5.3	6.4	7.0	7.4	7.8	8.1	8.6
135	4.7	5.8	6.6	7.1	7.5	7.9	8.5
150	3.9	4.9	5.8	6.6	7.0	7.5	8.2


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## seaduced8104

How about a Newport 33 with a shoal keel and standard sized rig????

Michael


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## Cptken

*Re C27 Polars*

See attachments


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## AdamLein

Cptken said:


> See attachments


Been looking for something like this for a while... don't suppose you happen to have the data tables in Excel or text?


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## Kramerski

*Polar diagram Beneteau First 45f5*

I'm desperately looking for the polar diagram of the Beneteau First 45f5. Unfotunately I'm not able to build up the polar diagram myself, since the boat is located in Hong Kong and I'm living in the Netherlands. In april, we are going to sail the Rolex South China Sea regatta and therefore I would like to have the polar diagram to use it with Raymarine RNS..

Thanks in advance,
Jurgen


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## seaduced8104

*Newport 33`*

Anything for a newport 33 with a shoal keel. four foot draft.

Thanks Michael


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## downeast450

Does anyone have them for an Islander 28?

Down


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## georgesoilis

*Re: Polar Diagrams-Newport41-Benetaeu 421*

Newport41

TWA	6	8	10	12	14	16	20
52	5.0	5.9	6.4	6.6	6.7	6.8	6.9
60	5.3	6.3	6.7	6.9	7.0	7.1	7.2
75 5.7	6.5 6.9	7.2	7.4	7.5	7.6
90	5.9	6.7	7.1	7.3	7.4	7.6	7.9
110	5.8	6.7	7.1	7.5	7.7	7.9	8.2
120	5.5	6.5	7.0	7.4	7.7	8.0	8.5
135	4.8	6.0	6.7	7.1	7.5	7.9	8.5
150	4.0	5.1	6.0	6.6	7.1	7.4	8.1

Benetaeu 421

TWA	6	8	10	12	14	16	20
52	5.5	6.4	6.9	7.1	7.3	7.4	7.4
60	5.9	6.8	7.2	7.4	7.5	7.6	7.7
75	6.2	7.1	7.5	7.7	7.9	8.0	8.2
90	6.3	7.2	7.6	7.8	8.1	8.3	8.5
110	6.2	7.1	7.7	8.0	8.3	8.5	8.8
120	5.8	6.9	7.5	8.0	8.3	8.6	9.1
135	5.0	6.3	7.1	7.6	8.1	8.5	9.1
150	4.2	5.3	6.3	7.0	7.5	8.0	8.7


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## JordanH

I've been curious about my Contessa 26... I wonder if anyone has bothered to create a polar for them.


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## keforion

Most interesting. 

Polar Diagrams used to be published with every sailboat review in the old issues of Yachting, Rudder and the like. You do not see them anymore. I wonder why. Perhaps the fact that they START at 52 degrees from the true wind angle is a clue. 

As a point of reference, my IOD, designed in 1938, and horribly slow, inefficient, and otherwise unsuitable by modern standards, sailed at an average of 39 degrees to the true wind as measured by the course over the ground between known landmarks on the shore of a relatively narrow channel (The Alameda Estuary, Oakland California.) This was before gps, so some experimental error is in there but this is an average of about a dozen runs up the same channel, roughly six legs, dead to windward usually, and it is taken from courses plotted on a chart, by reference to shore marks at each tack. And we were not pinching or trying to prove point. I only did the measurements after the fact when a question like this came up. We were just sailing.

I suppose if I were the NA of a thing that couldn't go much closer to the wind than 50, or even 45 degrees, I would not want the curves published either.


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## PalmettoSailor

Grendler said:


> Diagrams are from 33ft (Pearson, Contessa) up to 60ft (Centurion, Deerfoot, Swan). Sorry
> 
> Catalina I got only 36 model:
> 
> TWA	6	8	10	12	14	16	20
> 52	4.9	5.8	6.3	6.6	6.8	6.9	7.0
> 60	5.3	6.2	6.7	6.9	7.1	7.2	7.3
> 75	5.6	6.5	6.9	7.3	7.5	7.6	7.7
> 90	5.7	6.7	7.1	7.4	7.6	7.8	8.1
> 110	5.6	6.6	7.1	7.5	7.8	8.1	8.4
> 120	5.3	6.4	7.0	7.4	7.8	8.1	8.6
> 135	4.7	5.8	6.6	7.1	7.5	7.9	8.5
> 150	3.9	4.9	5.8	6.6	7.0	7.5	8.2


Thanks but these seem hoplessly optimistic for my TR, WK C36 with newish <4 y.o. dacron sails. I can only comment on the upwind to beam reach figures, since I believe these polars assume a spinniker once past a beam reach and my boat is not set up with spin gear.

Also, Since the wind angle is given as true, I'm assuming the wind speeds are also supposed to be true. Any idea if that's a valid assumption?


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## JordanH

PalmettoSailor, you are correct. They are true wind speed and direction.

I came across this PDF that explains it better than I can.
http://www.ockam.com/docs/SplainPolars.pdf


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## greggus2003

Grendler....you wouldn't happen to have Polars for a 1982 Pearson 37R would you?

Thanks in any case.

Greg


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## paulk

US Sailing has polars for just about anything with sails that floats, but they're not free or cheap. I believe their diagrams show angles of attack from closer to 0 degrees to 180. You can also create your own diagrams empirically, but it's a lot of work to document all the wind speeds, angles, and boat speeds.


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## Vanpupi

Does someone have the polars available from a gib'sea 444 or 442?


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## mickmoore

Hello, 
I am looking for a Polar Diagram for a Ranger 37... 
Would you happen to have one?
Best, Mick Moore
San Diego


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