Steve,

What you can not see is that the A mark in this picture is right behind the gals left elbow, and both of us were driving into the mark. The twist evident in this picture is from the fact that the main is not sheeted in anywhere near where it would be to go to weather efficiently and be able to judge against the numers being quoted in the other posts here.

My opinion of the square top sail to date is that it is a dream to sail. When trimmed, it does everything just as advertized. The problem I found in racing uni especially at this regatta where it was very gusty, was that without a crew, the sail was not often properly trimmed. With very small adjustments in the downhaul, one can keep the main flowing perfectly. When you are alone you pick your best guess at it and go.

With my current set up I have the ability to trim my sail out to be board flat if needed. I usually sail relatively light, so flatter is better for me. As you can see in the pic, making it very full is also possible. For going to weather, I set my rotation to get good transition around the leward side, which is slightly under rotated relative to traditional tear drop shapped masts. I then have my crew run the down haul so that my leach breaks equally up the sail as I sheet in. This becomes my reference point before we start, and during the leg they will downhaul more or less with the puffs. This way the sheeting is minimized, because when the sheet is eased a viscious circle is started, you get big twist to depower, but the sail also becomes very much fuller, which adds power and momentarily hurts your pointing ability, so you have to counter by letting out more sail than necessary.

Anyway, hope this did not add to your confusion.

Matt