Each rig may be described with a sail plan—a drawing of a vessel, viewed from the side, depicting its sails, the spars that carry them and some of the rigging that supports the rig. By extension, "sail plan" describes the arrangement of sails on a vessel. A well-designed sail plan should be balanced, requiring only light forces on the helm to keep the sailing craft on course. The fore-and-aft center of effort on a sail plan is usually slightly behind the center of resistance of the hull, so that the sailing craft will tend to turn into the wind if the helm is unattended. The height of the sail plan's center of effort above the surface is limited by the sailing craft's ability to avoid capsize, which is a function of its hull shape, ballast, or hull spacing (in the case of
catamarans and trimarans).
Types of rig •
Fore-and-aft rig features sails that run fore and aft (along the length of the sailing craft), controlled by lines called "sheets", that changes sides, as the bow passes through the wind from one side of the craft to the other. Fore-and-aft rig variants include: •
Bermuda rig (also known as a
Marconi rig) features a three-sided
mainsail. •
Gaff rig features a four-sided mainsail with the upper edge made fast to a
spar called a gaff. •
Spritsail rig features a four-sided mainsail with the aft upper corner supported by a diagonal spar, called a sprit, whose lower end meets the mast near the foot of the sail. •
Lateen rig features a three-sided sail set on a long yard, mounted at an angle on the mast and running in a fore-and-aft direction. •
Crab claw sail (also known as
Oceanic sprit or
Oceanic lateen) features a three-sided sail with spars on both the foot and the head. It's either mastless, supported by a "prop", or mounted on removable or fixed masts. •
Tanja sail (also known as
canted square/rectangular sail,
balance lugsail, or
boomed lugsail) features a four-sided sail with spars on both the foot and the head. It's mounted on removable or fixed masts. •
Square rig uses square sails as the major sails on a vessel. It is common for square rigged vessels to include some fore and aft sails, such as staysails. A mast may be referred to as a square rigged mast where square sails predominatethis would differentiate from other masts on the same vessel being fore-and-aft rigged, for example in a
barque.Square sails are generally suspended from
yards which, when at rest, are at right angles ("square") to the centre-line of the vessel. This differentiates them from fore-and-aft sails, which are aligned along the centre-line when at rest. Operationally, this means that square sails always present the same surface of the sail to the wind when propelling a vessel forward: they have a front and a back. Fore-and-aft sails can have either of their surfaces facing the wind when in use. Hence either vertical edge of a square sail may be the front (when sailing to windward) but fore-and-aft sails always have the same vertical edge at the front.
Types of sail Each form of rig requires its own type of sails. Among them are: • A
staysail (pronounced stays'l) is a fore-and-aft sail whose leading edge
(or luff) is hanked to a
stay. • A
headsail is any
sail forward of the foremost
mast on a sailing boat. It is usually a fore-and-aft sail, but on older sailing ships would include a square-sail on a
bowsprit. • A
jib is a headsail that is set in front of any other headsails, or in modern usage, may be the only headsail. It may be hanked to a stay, used in roller reefing or set flying (as in the more traditional cutter rigs). In a large vessel with many headsails, you may, for example, find a flying jib, outer-jib, inner-jib and then the fore-staysail. • A
genoa is a large jib that increases area by extending rearward of the mast. • A
spinnaker is a full sail of light material for use when sailing downwind in light airs. When in use, the jib or genoa would be lowered. • A
gennaker is a sail that is a cross between a genoa and a spinnaker. • A
mainsail ("mains'l") is a sail attached to the main mast. The principal types include: • A square-rig mainsail is a square sail attached at the bottom of the main mast. • A Bermuda-rig mainsail is a triangular sail with the luff attached to the mast with the foot or lower edge generally attached to a boom. • A
gaff-rig mainsail is a quadrilateral sail whose head is supported by a gaff. • A
spritsail-rig mainsail is a quadrilateral sail whose aft head is supported by a sprit. • A
lug sail is an asymmetric quadrilateral sail suspended on a spar and hoisted up the mast as a fore-and-aft sail. • A
mizzen sail is a small triangular or quadrilateral sail at the
stern of a boat. • A
steadying sail is a mizzen sail on motor vessels such as old-fashioned
drifters and
navy ships (such as ). The sail's prime function is to reduce rolling rather than to provide drive. Rigging-longship.svg|A
square sail is loose-footed, but may be attached to a spar, below. Rigging-junk-sail.svg|A
junk sail has multiple transverse
battens. Rigging-lug-sail.svg|A
lugsail has a tall asymmetrical shape. Rigging-lateen2-sail.svg|A
settee sail has an elongated asymmetrical shape. Sail plan catboat.svg|A
gaff rigged sail has a spar above and a boom below. Rigging-gunter-sail.svg|A
gunter rig has a vertical spar that extends vertically above the mast. Rigging-catboat-berm.svg|A
bermuda rigged sail has one edge attached to the mast. Rigging-lateen-sail.svg|A
lateen sail is loose-footed. Sail plan sunfish.svg|A
crabclaw sail has spars along two sides. Żagiel spinaker.svg|
Spinnakers are attached at their corners. Jib vs genoa.jpg|
Staysails include
jibs. == European and American vessels ==