RE: Magellan GPS and Down Haul

DAVID_KAUTZ@HP-Sunnyvale-om5.om.hp.com
Wed, 14 Apr 1999 08:59:13 -0700


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West Wight Potter Website at URL
http://www.lesbois.com/wwpotter/
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In the spirit of maintaining plenty of confusion about the "right" way to rig
the boat....

I've read recommendations to do the opposite - The argument being that the wind
speed increases with distance above the water (laminar flow). These folks say
you should hoist your sail as far as it will go with the downhaul released,
cleat the halyard and then set luff tension with the downhaul or Cunningham. The
same claim is used to justify "Tall" high aspect rigs and fully battened
mainsails with giant roaches near the head.

Personally, I suspect on rigs the size of the Potter's 6 inches up or down
doesn't make much difference. I'd go with minimizing the risk of getting hit on
the head by the boom

Dave Kautz
P-15 #1632 Tilly Lucy
Palo Alto, CA

______________________________ Reply Separator _________________________________
Subject: RE: Magellan GPS and Down Haul
Author: Non-HP-ej (ej@blarg.net) at hp-boise,mimegw7
Date: 4/14/99 6:41 AM

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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.