The purpose of the loose-footed main sail is to gain better sail shape. In addition the center of effort moves forward relieving weather helm and because the angle of the sail to the apparent wind improves so does power and the ability to point closer to the wind.
Many boat makers specify a main sail a with a bolt rope sewn into the foot to accommodate the groove along the boom. The out haul, often the most forgotten piece of hardware on a sailboat, adjusts the roach of the main sail. Located at the end of the boom it is little wonder a set-it and forget-it mentality thrives. Only small adjustments of the out haul are possible with the sail in the groove and often any increase in performance is not noticeable.
Basic Loose-Footed Main Sail Setup
The main sail is attached to the boom at the clew with a metal sail slide and at the tack in the normal fashion. As the wind picks up the main sail needs to be flattened in order to depower it and this is easily accomplished by bringing the clew to the end of the boom using the out haul. A multi-part out haul at the end of the boom makes adjustments easy.
When running down wind the advantage of sail shape is not as important as the amount of sail area carried in front of the wind. Instead of the boom reaching out far over the water the out haul can be adjusted to let the main sail billow forward instead.
Loose-Footed Main Sail Conversion
Depending upon the size of the boat converting the main sail to loose-footed is a relatively simple procedure. The foot of the modern main sail has a bolt rope sewn into it to allow the sail to slide into the groove in the boom. Some owners have added sail slides along the foot to make adjustments easier. If the bolt rope has sail slides installed the slides should be removed as they have no purpose when the sail is loose footed and may cause a problem during reefing.
To make the conversion remove the foot of the main sail from the boom by releasing the out haul and pulling forward along the bolt rope until it is free of the boom. Then attach a sail slide, preferably a metal one to the clew. Install the sail slide into the groove along the boom and attach the out haul. Each boat will be different however the basic idea is the same.
Because of the force of the wind on the sail, an out haul tackle is necessary to flatten the sail while reaching in higher winds. The out haul should be a three part tackle on small boats to as high as an eight part tackle for large ones.
Improved Sailboat Performance
On the SV HideAway, a shallow draft fixed keel boat, constant attention to the tiller had been necessary at all times. The least exhausting method to steer the tiller equipped boat in high wind was to sit on the leeward side of the boat using the coaming as a brace for an arm or a steering stick. Sailing 70 degrees off the wind was normal when reaching. Running down wind required the boom to be extended far out over the water and sailing in light winds required large head sails to reach hull speed.
Since converting to a loose-footed main sail, the SV HideAway can sail 45 degrees to the wind in most weather conditions with a simple self steering mechanism consisting of a spring on a continuous line. The boom seldom extends beyond the corners of the boat even while running. Gybing is also safer and easier. There is a noticeable increase in speed in relation to existing wind conditions. The increase in power allows fewer sail changes and the use of smaller head sails. Reefing is made safer since the nettles are tied around the sail instead of around the boom. There is no strain on the reefing cringles.
The freedom from constant steering and the speed gained increases the enjoyment of a day sail. However, the primary importance of sailing more effectively is shortening the time it takes to reach a far away cruising destination before sunset.
Matt Maloy - Matt Maloy, writer, artist and photographer has been sailing small boats for nearly thirty years. Based in Largo Florida, he chronicles ...
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