A fore-and-aft sail is a type of sail set along the centerline of a vessel, parallel to the keel rather than across it. Positioned aft (behind) a mast or stay, these sails (such as mainsails and jibs) can take wind on either side and are generally triangular, allowing superior sailing close to the wind.

Key Characteristics & Terms:
Orientation: Set lengthwise (fore-to-aft) rather than athwartships (crosswise).

Components: Often features a mast, boom, and rigging allowing the sail to pivot.

Types: Includes Marconi (triangular), gaff, lateen, and staysails.

Comparison: Contrasts with square-rigged ships, which carry sails on yards perpendicular to the hull.

Usage: Typical of modern sloops, cutters, and schooners.