If it''s possible to roller-reef your boom, you will notice that the boom has a couple of specific features:
1) it''s round
2) it spins freely at the gooseneck (probably)
3) the mainsheet attaches at the end
34 there is a specially-built vang that will work when the sail is wound around the boom.
There are some other techniques to use to de-power a sail when the wind kicks up if you are reefless:
Make sure you''ve hauled the main up tight in the first place. Snug that halyard before you get into stiff wind.
In wind, you want a "flat" (less curved) sail. For the main, tighten the outhaul, and snug down the boom vang to prevent lift, even when working to weather.
For the jib
, as the breeze freshens, sliding the jib
fairleads forward will allow you to tighten the jib
down so that the leech (back edge) is tight (curve is relatively flat looking from the cockpit) and not as efficent at drawing at the wind. When the breeze stiffens and this is no longer effective, slide the fairleads all the way back and keep the trim loose: wind will now spill out of the twist in the jib
and the point of pressure has moved away from the front (luff) of the sail (same principle as discussion for mailsail below).
Tightening the outhaul will flatten the profile of the mainsail, reducing it''s lift (power).
Sliding the traveller completely downwind will de-power the main by allowing wind to spill out of the sail instead of driving it.
Keeping the mainsheet trimmed loosely as well will move the force of the wind back along the sail, away from the luff (the 12 inches of canvas closest to the mast). When the pressure hits the sail farther back, it drives the boat w/ less power. You can see the pressure eased along the front of the sail as the point of pressure moves back. It may not look graceful, but it''s acutally a very seaman-like maneuver.
When the wind is heavy and you''ve done all the above, you can "pinch up." Steer the boat close-hauled, and then just a bit higher into the wind. Steer as high as you can without stalling. This causes the wind to travel around the sail with less disturbance and less lift is created. When on this extreme point, you must be careful not to let the bows fall off the wind: you will heel over, round up hard and lose your boatspeed.
In most boats, dousing (hauling down) the jib is an effective way to reduce power. You may lose a bit of headway and gain some leeway (slippage), but there is plenty of wind to drive you along. The only difference you will notice is likely to be less heel and less tendency for rounding up. (Okay, maybe some lee helm as well).
I sail a small boat without reefs, and have read about and practiced this quite a bit. When used in conunction, these techniques can turn a panic into a thrilling, but still controlled, ride, and make you a better sailor.
P.S. If your sail is "blown out" (stretched-out) you will not be able to flatten it physically: it''s time to go shopping for a new sail (one with reefpoints!)