Loose Foot

A Titanium loose-footed mainsail. A velcro strap around the boom takes the place of a clew slug or clew car.

Most of today’s mainsails are loose-footed with nothing attaching the sail to the boom other than the tack at the gooseneck and the clew on the outhaul. As seen here, a loose-footed mainsail is able to produce a much more aerodynamic shape down low which enhances the performance of the sail.

In the past, the bottom edge of the main was attached to the boom with slides or a boltrope, but the sail could not achieve a proper aerodynamic shape without building in an expensive shelf foot.

An extra advantage of the loose foot is that with just two attachment points, bending on the mainsail and removing it are much easier. 

Not attaching the foot of the sail to the boom  provides a much better aerodynamic shape without reducing strength