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Old 10-12-2012
bobperry bobperry is offline
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Re: Fin vs bulb vs wing keels

We may be on thin ice here lumping all wing keels into one category. There is no question that when you are up gainst a hard draft restrcition a wing can work quite well.
The Aussie winged keel worked well in conjunction with the upside down profile of that keel and the extra long tip chord with it's vortex problems.

When I designed the Islander 34 we did a 5.5' draft wing keel and a 7' draft straight fin. Islander built one of each as hulls 1 and 2. They were launched the same day with sails from the same sailmaker. I flew down with one of my helpers, a very good sailor, and for two days we raced these two boats against each other. The difference in speed was minimal if present at all. And, I was a skeptic to begin with. But after trading boats and sailing them upwind and down. I came away a believer. The wing keel boat was a bit slower off the wind, not much. Up wind the two boats were pretty much identical in VMG. This is not theory. This is first hand sailing experience with two identical boats.

But wings to be effective have to have aspect ratio just like fins. Short, thick stubby wings, like we have seen on many production models, are not efficient. They may do a nice job at lowering the VCG but they can be a lot of drag and be wonderful Bruce type anchors if you get stuck in the mud.

All I'm saying is to treat wings on keels on an individual basis.
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Last edited by bobperry; 10-12-2012 at 06:40 PM.
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