Advantages of a Loose-Footed Sail

A mainsail for the typical cruising sailboat must perform well under every condition. One factor to consider is whether the sail attaches along the foot (bottom edge) of the sail or whether it is "loose." Loose-footed sails, which attach only at the fore and aft edges, carry certain advantages and disadvantages that distinguish them from attached-foot sails.

  1. Terminology

    • The modern mainsail has several basic parts to it. The luff, the leading edge of the sail, attaches to the mast. The leach is the trailing end of the sail, directly opposite the luff. The foot of the sail is the lower edge, and it includes the tack and the clew, which refer to the front and back corners of the foot, respectively. These corners attach to the boom, a long pole extending perpendicularly to the mast. One action affected by a loose-footed sail is reefing, which consists of making the sail artificially smaller to prevent high winds from capsizing the boat.

    Loose-Footed Advantages

    • Loose-footed sails attach to the boom only at the tack and the clew, leaving most of the foot free to move with the wind. Sails attached in this way are easier to reef manually by tying a rope, also known as a line, around the foot and the leach. Loose-footed sails also tend to form a better shape for catching the wind, since the sail can fill outward a bit more.

    Loose-Footed Disadvantages

    • Attached-foot sails have the advantage in several ways, however. Loose-footed sails put much more pressure on the clew and tack, whereas attached-foot sails distribute pressure more evenly. In addition, some masts come with mechanical reefing devices that rely on an attached foot to maintain the shape of the sail. Loose-footed sails also tend to chafe more, since they pass back and forth over the boom itself.

    History

    • Nearly all modern sail fittings are attached-foot rigs as of 2011, as they are generally more durable. Attached-foot sails rely on having metal booms, as wooden ones are unsuitable for the types of slides that typically fasten the foot of the sail to the boom. While you may be able to find loose-footed sails today, racers and most enthusiasts do not sail with them.