Graham's writing is always interesting.
Since his text went over the side this time, I played a little trick with the link to crimp the text (Shift +CR).
Graham writes:
"Arion is currently in the Breakwater Marina, Townsville, and I have been doing something I don't usually, going for daysails. I sail out of the marina into the SE trades and beat to windward for several hours, then turn around and run back in. It might take me 4 hours to beat out into moderate seas, but the run home is swift, only taking an hour or so. Arion was designed for fast and easy running, no rounding up or heavy rolling, but it is the windward work that has surprised me. Arion's new, so called flat-cut sail goes to windward like a freight train, sailing at 3 knots in 12 knots of breeze (ok, all things are relative, but we are talking about a 24ft, 5 ton boat with 10 ft beam), with the windvane set at 35 degrees and tacking through 90 degrees. When the wind and sea start getting up, 15 plus knots, I crack the windvane off to 45 degrees and tack through 100 degrees.
So what's the secret? The short yard, giving an almost horizontal leach for the top panel lets the upper, unsheeted batten twist off, like a flat-topped racing bermudian main, plus I put about 20mm of round in the seams along the battens of the top three, fanned panels. But, and here is something that perplexes me, I appear to have a slight amount of camber in the lower four, so-called flat-cut panels. How did this happen? It seems that the deep hollows we cut into the leach really flatten out the back of each panel, while the straight-cut luff allows the front of each panel to scallop slightly, and voila - just the teeniest bit of camber. I don't know how much, just a teeny bit. It is just dumb luck. You can see it in this photo: "
http://www.junkrigassociation.org/Sys/PublicProfile/3295421/
PhotoAlbums/58385873
Woops, I had to make a new link, as well - hope it was the right one
Arne.