Trimming the Main Sail

"Over my years of racing, I've learned to watch the angle of the top batten to try to point as close to the wind as possible. Sighting from under the boom, I trim the sheet until the two are parallel, except in waves or heavy winds, when it's much faster to let the sail twist open a little. This approach has worked on cruising boats I've sailed, too... new sails can do lots of clever tricks--they can flake, they roll inside the boom, or they roll in the mast. But a rapidly increasing number are sold for in-mast furlers and have vertical battens or no battens at all.

"If the bow falls off when I ease the mainsheet in a puff, I know that's a sign of leeward helm, so maybe I should tighten the boom vang to help the leech hold its shape. This can be done even if you have a solid, non-adjustable vang with an in-boom furler; according to Dave Anderson of Schaefer, which makes the Boom Furler, you can just "turn the mandrel [furler] a little." Want to solve the more common problem of weather helm? I start by tightening the outhaul, although I've learned the hard way that this has its limits. A tired outhaul can fail if you're too enthusiastic on the winch handle."

- Cruising World