What I do to trim the sail is... Sail Trim Posted By: CarlHaddick, Horizon Cat/Picnic Cat, Central Texas  he article you're referring to is probably in the January 2007 issue of Sailing magazine, (See page 19), called  'Technique - Gaff-Rigged Sail Trim'. An excellent article. I would add their 'deep throat' technique is verging on  overtensioning the peak halyard, but it looks like it works. You can see in the pictures it's close to putting peak-to-tack  wrinkles in the sail. I haven't experimented with deep throat mode yet, but will on my next sail. The tradeoff, I bet, is the  detrimental effect of vertical wrinkles starting to appear versus the deeper foil shape he recommends for heavy air. T  When my peak halyard is too loose, it feels like stomping on the gas pedal when I trim it in - the peak trim is critical, and  getting it right can accelerate the boat much like sheeting in. There is also a nice side effect in the way the sail behaves best with a precise angle of attack. In the article it talks about  the gaff rig being forgiving, with a wide groove in terms of angle of attack. The angle of attack they are talking about is the  angle of the apparent wind to the sail. Luffing up or falling off, sheeting in or out, those are the ways you control the angle  of attack. The author says to get best performance when close-hauled you need to sail on the edge of the groove closest to the wind.  I've found that to be helpful. In other words, bring your boat close to the weather and sheet in. Head up enough to put a flutter in the luff, and then fall  off just a bit. That's the best part of the groove in the author's opinion, and that's been my experience as well. When I'm trimmed like that, the leech tales fly pretty much straight back. If they start curling leeward, that's getting off  that windward side of the groove. The nice side effect is that when you're trimmed that close moving the tiller just four inches to the lee will immediately  detune the rig enough to handle a lot of gusts. If you can point up a smidge every time you need to set the boat back down  instead of sheeting out, you keep your speed up and sidestepping higher upwind is often a favorable thing to do. On the other hand, I don't think the catboat's reputation for not sailing well close-hauled is really deserved. My 20 foot  Horizon Cat has a 17 foot boom, and the geometry of the rig makes it look different. A 30 foot sloop with a high aspect rig  might only have an 8 foot boom. At more than twice the boom length, my boat will have its clew more than twice as far  away from the boat's centerline with the sails set to the same angle. Anyway, it is indeed a good article. Sailing magazine is worth subscribing to. There is a point going to windward that you can over trim the sail, but you'll know it because, 1st the leach telltales start  to go forward, and the boat slows down. Jim's idea about traveling to windward and using less mainsheet, does bring the  boom more toward the center, but in light air it is still over the edge of the boom gallows, but a fuller sail and does help to  point a little higher with same boat speed. Pull it in 2 in. to much and you stall. I know the Sun Cat is under canvassed, so I didn't expect it to do to good against other boats in those conditions, Heck, it's  like other boats sailing with a reef in light air, But the real test will be when its blowing 12 to 15, just enough not to reef,  that'll be the day I'll be telling those sloops, "C'MON, YOU WANT A PIECE OF ME NOW", "YEA, WHOSE YOUR  DADDY NOW." Posted By: Mark Milam Nonsuch 33, SunCat cabinless, LA  lace several tell tales on leach and draft of sail. Then I play with the gaff position and mainsheet, outhaul and  downhaul to get then all flying back for that wind and enough draft for power, like as in light air or waves, a flatter  sail for smooth water and more wind. Just for the record, I've been racing since I was 14. We did win Nationals in the F-27  class 3 times. I just approach the cat boat sail like any sail, you have to get all the air flowing over it and the only way for  me is to use tell tales. So many boats don't even have any. Another thing about the Sun Cat sail is the gaff goes really  high, almost makes it a Marconi rig as compared to other tradition gaff rigs. So I think, and I'm no expert, you would trim  it more toward a Marconi rig. I know that playing with the gaff, and not much at that, made a significant difference in air  flow and shape going to windward and off the wind. I found myself adjusting it for both conditions several times during  the race, to get good air flow. P  17