Bahia 46: Polar Diagram for a Bahia 46

[Russell7171]

Title says it all.
Anyone got one?
Please email to me at poulston@me.com
Russell

[Kiwikat]

Hi Russell,

I've got one somewhere, not sure if it is here on the boat or back in Oz. Will have a dig around the boat, otherwise will definately get one for you when we go back across the ditch next week. We are currently on board, mooching around Waiheke in Auckland.

Cheers
Lisa

[Kiwikat]

Of course it was on my laptop all the time

[lateral]

What actual wind speed is the red plot?

[Kiwikat]

Originally Posted by lateral

What actual wind speed is the red plot?

20 knots

[Bloodhound]

Originally Posted by Kiwikat

Of course it was on my laptop all the time

The polar diagram is very interesting. Is there a central place where these can be found for other boats? Of course, I'm interested in a diagram for a Westsail 32.

Ralph

[Russell7171]

Cheers mate. Just left Auckville. Over in Brissie seeing my sister. Will be in Bay of Islands in 4 weeks to spend a week with a couple on their cat - met them in the Caribbean. Where do you cruise?

[Kiwikat]

Ralph, sorry cannot help you with that one.

Russell, as you are the OP I guess it's ok to go off topic here. We largely cruise the Hauraki Gulf - Waiheke, Coro, The Barrier etc. We have not long just returned from nearly four weeks up at the Bay and beyond, which we often do over the Xmas period but the weather has been so lousey here that it was not the most pleasureable trip this year.

I remember Ta-b when she was listed for sale, at the time when you must have bought her. That is when we decided we wanted a Bahia.

Cheers

[colemj]

That is an unusual bump between 90 and 100* - it has to be a spinnaker or other downwind sail used there.

Mark

[jzk]

I believe that FP publishes their polars at 20 knots only. It would be nice to see what they are for 10 knots and 15 knots. Maybe even 5 knots?

[donradcliffe]

So what is your experience--does the boat sail to this polar diagram??

Better?
Worse?

Does it really do 6.5 knots on the wind at 40 degrees true (30 degrees apparent)?

[Kiwikat]

I believe the polars are done with mainsail and genoa only and of course empty with empty tanks etc. I think they would be pretty accurate on a brand new boat. The only trouble is that you start loading them up with all the cruising goodies and the accuracy is gone forever as far as speed goes but the shape would still be fairly much the same. I cannot much comment on speed here myself as we have just spent a couple of hours in the water attempting to remove the amazon jungle off the bottom . Sadly the antifoul the previous owner put on must have been the cheapest crap he could buy and it has almost completely fallen off in less than a year and we have not yet had the opportunity to haul her out. The reason for the speed bump is that these cats just love that angle to the wind. You can just feel them light up when you bring them around to that angle. As for polars at 10 and 5 knots, it would not be a pretty picture at all (unless you sneak an engine on).

[bosinsky]

Hi,

First post, hope it will help...

The Bahia sails better than Polar, if you have good sails.

We have a very nice inventory and with 23KT AWS we are doing 8/8.5 Kt boat speed for 35 to 40 AWA. (Verified with GPS)

I think best up wind VMG is around 35AWA.

I will make new polar with the Optima software, after the next antifouling.

10kt motoring with 40hp engines @2400 rpm (craftsman engine) and 3 blades flexofold propellers. 9KT@2200rpm, our cruising speed.

And with nice low wind sail like a screacher you will be surprised by the speed.

The Bahia is very good, in fact, better than expected.

[Russell7171]

Thanks to both KiwiKat and Bosinsky for your input.
We have a pair of Kiwiprops but only use one engine when motoring. Our speeds are obviously a way way less than yours when motoring. Mind you, have just had my bottom scraped (as it were) and will be plopping on copper coat over a smooth bottom. We hope that will increase the speed considerably.
Watch this space.
Used to have those high end US feathering props on, forgotten the name, but you need to be a damn nuclear physicist to put the buggers back on. Prefer to do my own servicing so we now save a few bob by doing it all myself.
They are currently being serviced in Auckland. Sure puts the weight up when flying with those puppies in my luggage.

Good to see you are happy with your Bahia. We had a great trip across the pond, with winds around 35 for quite a while. Wind angle not quite up the freckle (as it were), sort of on the stern quarter. Ran a few 220 mile days. Comfortable at 10 to 12 knots when the wind picked up a tad more.

[Gaelen]

What is the diameter and pitch of your props?

Originally Posted by bosinsky

Hi,

First post, hope it will help...

The Bahia sails better than Polar, if you have good sails.

We have a very nice inventory and with 23KT AWS we are doing 8/8.5 Kt boat speed for 35 to 40 AWA. (Verified with GPS)

I think best up wind VMG is around 35AWA.

I will make new polar with the Optima software, after the next antifouling.

10kt motoring with 40hp engines @2400 rpm (craftsman engine) and 3 blades flexofold propellers. 9KT@2200rpm, our cruising speed.

And with nice low wind sail like a screacher you will be surprised by the speed.

The Bahia is very good, in fact, better than expected.