[Rhodes22-list] UPS and sail trim

[Mark Kaynor]

All,

Just before we left Blacksburg for Deltaville I was just going through some
back issues of Cruising World and came a cross a three articles in the May
(I'm pretty sure it was May) issue regarding light wind sailing. They
discuss code 0 sails like the Doyle UPS, and have some good downwind /
lightwind techniques.

In the same vein, this web site has been being discussed on the Tayana site
and seems like it would be of benefit to any sailor who wants to learn how
to better trim their sails: http://www.arvelgentry.com/index.html

The fellow who posted the link included the following: 

I've mentioned several times about the precision of sail trim and its ease
in doing so.  
The following URLs are the recently recompiled Arvel Gentry website that
contain the 'seminal' articles of the aerodynamics of sails written by the
penultimate sailor/aerodynamicist that radically changed the way that
sailors interpret the flow, trim and other 'goodies' about sails.  Gentry
was the one who 'de-bunked' the slot effect, and perhaps is the ONLY one who
correctly explained the interaction of a staysail flown under a genoa.
Gentry's articles 'revolutionized' the way sailors interpreted and set their
sails, and in effect was the 'secret weapon' used by the American entries of
the America's Cup boats .... you remember back when the US boats WON. 

And 

The articles on "Gentry Tufts"  (sail trim, better close winded, etc.) that
appeared in Sail Magazine were the 'landmark'.  I got introduced to these
articles (then top secret info) by several crew members of Americas Cup
boats in the 70s-80s ..... and from then on I hardly ever got less than a
second place when racing.  Gentry was the 'aero' consultant to the American
ACup boats for about 15 years. Those AC boats weren't better than their
competitors, they were 'sailed better' due to the Gentry Tufts, etc. 
More importantly the 'tuft system' will allow you to keep sailing your
Tayana when other boats are either turning on their engines ... or are
heaving-to.  

FYI, for those that are strictly non-technical the "Sail Trim Guide" by Don
Guilette (a world class C30 racer) is a wonderful guide to sail trim and
shaping. Don took the Gentry articles and boiled them down into *very*
simple and easy to understand directions (without lengthy explanation) ....
available from www.sailboatowners.com.  Don's guide will promote good sail
draft location, proper amount of sail draft, as well as other important
trim/shape considerations (twist, etc.) .   Well worth the few $$.   

Mark Kaynor