RE: Magellan GPS and Down Haul

Eric Johnson (ej@blarg.net)
Wed, 14 Apr 1999 06:41:02 -0700


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West Wight Potter Website at URL
http://www.lesbois.com/wwpotter/
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> It really works. Received an invitation to test drive a Cadillac, did so.
> Sent the form into GM and received a free Magellan 300 GPS within
> 3 weeks.
> Now I have to learn to use it. Current retail value = $99. Not bad for 45
> minutes of time.

Cool!

> Have a question. How do you determine how much down haul pressure
> to apply to
> the main sail? Does it vary for different wind conditions?

Yes. Generally run it tight enough to eliminate any horizontal wrinkles in
the luff, but not so tight as to cause vertical wrinkles. I'm sure Judy will
elaborate. :)

>Should
> the boom
> ride as high as it can without coming out through the wide spot
> in the slot?

Best performance is theoretically when the boom (and therefore the entire
sail) is as low as possible, since the cabin and deck act to reduce the
amount of wind spilled beneath the sail causing induced drag. I have
experimented with this and my gut reaction is that indeed it does help. I
suspect a few of you are going to disagree with me :) This is a cheap
performance trick not always mentioned in the sailing books since on most
craft, there are either fixed goosenecks or class rules dictating the
position of the boom.

>From a standpoint of practicality, when guest are aboard and I'm not racing,
I run the boom as high as possible for headroom.

> I like the idea of the second sail stop to prevent the boom from
> sliding all
> the way down, particularly when leaving boom and sails attached.

I solve this problem in a different way. I have a dowel with holes drilled
into in, slid into the sail track below the boom. Into it from outside is
attached a clamcleat for the downhaul. This allows me a little greater
freedom in boom positioning, and the clamcleat is 100 times faster than the
horn cleat it replaces.