[Rhodes22-list] UPS and sail trim

[Mark Kaynor]

Bill,

My pleasure. I haven't actually used the system yet, but I do have some
experience imagining using it <g>. I recently crewed on Joss, a 1960s wooden
ketch in the Leukemia regatta here in Deltaville. I was sucking beers and
calling the jib trim imagining all those extra telltales - it was really
interesting (and apparently successful, seeing as we won) to think in terms
of the flow over the entire sail as opposed to just at the location of the
two sets of tells. Pretty cool.

Mark

-----Original Message-----
From: rhodes22-list-bounces at rhodes22.org
[mailto:rhodes22-list-bounces at rhodes22.org] On Behalf Of Bill Effros
Sent: Wednesday, July 20, 2005 8:11 AM
To: The Rhodes 22 mail list
Subject: Re: [Rhodes22-list] UPS and sail trim

Mark,

Thanks for posting this information a second time for my benefit.  I just
got to this (I keep the interesting stuff I don't have time to read put
aside for when I have a little more time--I just got to this, after spending
a lot of time on the Gentry site because you mentioned it in a subsequent
post.)

At some point you must have realized I had never read the original, and you
posted the information again.  Thank you.

With regard to the Gentry site--it is fascinating!  I will surely rearrange
my tell tales this winter.  (My system was strictly "seat of the pants" -- I
could see I was headed in the right direction, but I also knew I didn't know
what to do next.)

I will test many of the concepts Gentry introduces using my current
tell-tale system this summer.  But I almost can't wait to take the mast down
to set up the new tell-tale system for next year.  One of the most important
modifications I will make to the Gentry system is putting the tell-tales
where they can be continuously seen from captain's chairs.  I find it is
more important at this phase of my education to be able to continually
monitor sail shape, than it is to strategically monitor sail shape in the
aerodynamically most significant zones of the sail.

You and Arvel have given me a lot to work with.

Bill Effros

Mark Kaynor wrote:

>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
>
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>
>  
>
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