Spritsail

thumb|Diagram of a four-cornered spritsail The spritsail is a four-sided, fore-and-aft sail that is supported at its highest points by the mast and a diagonally running spar known as the sprit. The foot of the sail can be stretched by a boom or held loose-footed just by its sheets. A spritsail has four corners: the throat, peak, clew, and tack. The Spritsail can also be used to describe a rig that uses a spritsail.

thumb|Spritsails appeared in the 2nd century BC in the Aegean Sea on small Greek craft. Here a spritsail used on a Roman merchant ship (3rd century AD). Historically, spritsails were the first European fore-and-aft rigs, appearing in Greco-Roman navigation in the 2nd century BC.