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Old 06-03-2012
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US27inKS US27inKS is offline
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Keel shape and pointing

A few years ago I helped a friend template his keel.

How to template a keel

The shape started out as a complete disaster, and we had very little to go on for specs. So we guessed. Now I'm second guessing the decision on what shape to use.

I've known all along that we have been out-pointed by every other boat in our PHRF fleet, but this weekend I tracked it using a great little app I found for my phone. In playing back the track from the race I can see that our actual tacking angle was 105 to 110 degrees in 10kt winds at 5kt boat speed. This contradicts what we see on the masthead wind indicator that has been carefully set at 90 degrees. We can pinch a little higher than 45 degrees to the wind, but we lose enough boat speed to make it unpalatable for very long. So I have to believe that we're just making that much leeway.

My question for you super smart guys here is this: given the foil shape that we used (and it looks really fast), should we have opted for something a little more forgiving like an 0010 foil shape that would produce more lift at lower speed vs the 63-009 (with an actual foil thickness of 9.786%) foil with lower drag? Would the 0010 foil given us less leeway?

The other possibilities are that I suck at trimming, or Bill sucks at driving, or both.
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John USYacht 27 "Cora Lee"
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