Sail FAQs:

Q: Is sail a tensile structure—made from fabric or other membrane materials—that uses wind power to propel sailing craft?

A: Yes, and including sailing ships, sailboats, windsurfers, ice boats, and even sail-powered land vehicles.

Q: Were sails developed in Europe?

A: Yes, such as the spritsail, gaff rig, jib, genoa, staysail, and Bermuda rig mainsail, improving the upwind sailing ability of European vessels.

Q: Are sails part of the running rigging and differ between square and fore-and-aft rigs?

A: Yes.

Q: Are sails laminated sails formed over a curved mold and adhered together into a shape that does not lie flat?

A: Yes.

Q: Are sails tensile structures?

A: Yes, so the role of a seam is to transmit a tensile load from panel to panel.

Q: Were sails made from flax or cotton canvas?

A: Yes.

Q: Is sail aligned with the apparent wind?

A: Yes, than it can with the entry point not aligned, because of a combination of the diminished force from airflow around the sail and the diminished apparent wind from the velocity of the craft.

Q: Was sail used by Stars and Stripes?

A: Yes, and the defender which won the 1988 America's Cup, and by USA-17, the challenger which won the 2010 America's Cup.

Q: Are sails unable to generate propulsive force if they are aligned too closely to the wind?

A: Yes.

Q: Is sail defined by its edges and corners in the plane of the sail?

A: Yes, and laid out on a flat surface.

Q: Are sails rotated from side to side?

A: Yes.

Q: Are sails more likely to be bi-radial?

A: Yes, since there is very little stress at the tack, whereas head sails are more likely to be tri-radial, because they are tensioned at their corners.

Q: Are sails called the head?

A: Yes, and the leading edge is called the luff on fore-and-aft sails and on windward leech symmetrical sails, the trailing edge is the leech, and the bottom edge is the foot.

Q: Is sail a clew?

A: Yes.

Q: Are sails carried on horizontal spars?

A: Yes, and which are perpendicular or square, to the keel of the vessel and to the masts.