A jib is a triangular staysail that sets ahead of the foremast of a sailing vessel. Its tack is fixed to the bowsprit, to the bow, jibs and spinnakers are the two main types of headsails on a modern boat. Boats may be sailed using a jib alone, more commonly jib make a direct contribution to propulsion. Generally, a jibs most crucial function is as an airfoil, increasing performance, on boats with only one jib, it is common for the clew of the jib to be further aft than the mast, meaning the jib and mainsail overlap. An overlapping jib is called a genoa jib or simply a genoa and these are efficiently used when reaching more broadly than a close reach. Alternatively, a boat may carry smaller jibs, to compensate aerodynamics when the sail is reefed. On a boat with two staysails the inner sail is called the staysail, and the outer is called the jib and this combination of two staysails is called a cutter rig and a boat with one mast rigged with two staysails and a mainsail is called a cutter. On cruising yachts, and nearly all racing sailboats, the jib needs to be worked when tacking, on these yachts, there are two sheets attached to the clew of the jib. As the yacht comes head to wind during a tack, the sheet is released. This sheet becomes the new active sheet until the next tack, schooners typically have up to three jibs. The foremost one sets on the topmast forestay and is called the jib topsail, a second on the main forestay is called the jib. Actually, all three sails are both jibs and staysails in the generic sense, jibs, but not staysails, could also be set flying, i. e. not attached to the standing rigging. A large square-rigged ship typically has four jibs, but could have as many as six, from forward to aft, these sails are called, Jib of jibs Spindle jib Flying jib Outer jib Inner jib Fore staysail. The first two were used except by clipper ships in light winds and were usually set flying. A storm jib was a small jib of heavy canvas set to a stay to help to control the ship in bad weather
Three of the four jibs are in pink.
A jib, left, compared to a genoa, right. The foretriangle is outlined in red.