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post #4 of Old 10-29-2004
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Main Sail Shape


The outhaul is a control line that pulls the clew (aft bottom corner) of the main backwards. Look at your boom and figure out what the clew is attached to. On some boats it''s attached to a piece of hardware that can be moved around at the dock but has no control line. If so, then you don''t have an outhaul.

If the outhaul is attached, then it''s led forward inside the boom and usually winds up with a jam cleat or similar securing device somewhere on the boom towards the mast. To adjust, you need to unload the sail and yank the outhaul hard. What you''re trying to do in a stiff breeze is pull all 3 corners of the main away from the center of the main, causing the main to flatten out.

There is sometimes a control line attached just above the tack (forward bottom corner) of the main, called a cunningham (sometimes called a downhaul), that lets you exert pull down on the tack as well. So your 3 tensioning controls are:
- Halyard (tensions head)
- Outhaul (tensions clew)
- Cunninngham (tensions tack)

Another main-flattening tool is an adjustable backstay. Look at your backstay to see if there is some mode of on-the-water adjustment. tightening the backstay will also help to flatten the sail, because it pulls the masthead backwards a bit, flexing the mast into a shallow curve, which matches the curve built into the main (the sides of the triangle of the main are not straight--they are usually curved outwards slightly for shape.)

If you have a light boom that can flex somewhat and an attached foot on your main, tightening the boom vang will also help flatten out by pulling the foot of the sail down.

All of the above might reduce weather helm by 10 degrees or so. You want some weather helm, right? Maybe 3-5 degrees. That gives you better lift from the rudder, reduces leeway and improves pointing. After that, the first steps are to flatten the main with the above controls (whichever you have).

Next, to further reduce weather helm, if you have a traveller that can be adjusted under load, ease it. It might be worth your while to upgrade your traveller with a better arrangement so you can ease it from the cockpit, and play it in gusts.

Reefing the main is the last stage of reducing weather helm. Sounds like you already do this. I think you''re ahead of the game already--most people don''t reef early enough. It''s amazing how much easier boats will sail and how much more fun you can have with a reefed main! Especially if you don''t wait to reef until it''s howling.

Hope above helps.

bob_walden is offline  
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