On 2008-08-09 21:06:04 -0400, "Roger Long" said:

The performance difference between the 150%
and the working jib (about a 110% overlap) even in light air and on reaches
was much less than the difference in sail area would indicate.

Upwind, the difference is pretty much the difference in length about a
foot or so behind the luff, where the power comes from. There's some
benefit from less drag in the smaller sail, too.

--
Jere Lull
Xan-à-Deux -- Tanzer 28 #4 out of Tolchester, MD
Xan's pages: http://web.mac.com/jerelull/iWeb/Xan/
Our BVI trips & tips: http://homepage.mac.com/jerelull/BVI/

"Jere Lull" wrote

Upwind, the difference is pretty much the difference in length about a
foot or so behind the luff, where the power comes from. There's some
benefit from less drag in the smaller sail, too.


Exactly. My old Genoa, reefed down to the area the boat could carry in fresh
conditions, had less leading edge than the working jib. I now have just a
bit more area than the old working jib with full length leading edge and
more leading edge when reefed to the old working jib size. The overlap area
is really only effective reaching and, if you want the 150% area for light
air, better to put it in an asym.

--
Roger Long