Tacking (sailing)

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Tacking: Sailing the craft into the wind from the port tack to the starboard tack. Wende (Segeln).png
Tacking: Sailing the craft into the wind from the port tack to the starboard tack.
Beating to windward on a series of port and starboard tacks, tacking between each at points 1, 2, and 3. Beating to windward.svg
Beating to windward on a series of port and starboard tacks, tacking between each at points 1, 2, and 3.

Tacking or coming about is a sailing maneuver by which a sailing craft (sailing vessel, ice boat, or land yacht), whose next destination is into the wind, turns its bow toward and through the wind so that the direction from which the wind blows changes from one side of the boat to the other, allowing progress in the desired direction. [1] Sailing vessels are unable to sail higher than a certain angle towards the wind, so "beating to windward" in a zig-zag fashion with a series of tacking maneuvers, allows a vessel to sail towards a destination that is closer to the wind that the vessel can sail directly.

Contents

A sailing craft, whose course is downwind, jibes (or "wears" if square-rigged) by having the apparent wind cross the stern from one tack to the other. [2] [3] High-performance sailing craft may tack, rather than jibe, downwind, when the apparent wind is well forward.

Beating to windward

Points of sail: the shaded area is the "no-sail" zone. Points of sail.svg
Points of sail: the shaded area is the "no-sail" zone.
Beating to windward on short (P1), medium (P2), and long (P3) tacks, each with a progressively wider corridor over the water. Tacking Intervals.svg
Beating to windward on short (P1), medium (P2), and long (P3) tacks, each with a progressively wider corridor over the water.

Sails are limited in how close to the direction of the wind they can power a sailing craft. The area towards the wind defining those limits is called the "no-sail zone". To travel towards a destination that is within the no-sail zone, a craft must perform a series of zig-zag maneuvers in that direction, maintaining a course to the right or the left that allows the sail(s) to generate power. Each such course is a "tack". The act of transitioning from one tack to the other is called "tacking" or "coming about". [2] Sailing on a series of courses that are close to the craft's windward limitation (close-hauled) is called "beating to windward". [4]

For various sailing craft

The method for tacking of sailing craft differs, depending on whether they are fore-and aft, square-rigged, a windsurfer, a kitesurfer, or a proa.

The bearing from a sailing craft's current location to a destination or racing mark that lies within the no-sail zone, may lie on one side or other of being directly upwind. The tack on that side is "favored", because the destination lies closest to the craft's highest point of sail—its "best course" is close-hauled on that tack. Wind shifts that improve the angle towards the destination are called "lifts"; those that increase the angle away from the destination are called "headers". A sufficiently large wind shift may cause the destination to lie on the opposite side of the direction from which the destination or mark lies and indicate a tack to the favored side—tacking on a header. [13]

Apparent wind sailing

High-performance sailing craft, such as sailing catamarans, sailing hydrofoils, ice boats and land-sailing craft, may be capable of speeds exceeding the true wind speed, sailing off the wind. Because the speed of the craft is a dominant contributor to the apparent wind, the apparent wind angle shifts forward. Such sailing craft may tack, while going downwind, under the principle of apparent wind sailing. [14]

Racing

Sailing race courses may be triangular, windward-leeward triangular, or simply windward-leeward, each of which involves at least one leg directly to windward. [15] The windward mark may favor a best course on a given tack, until the wind shifts significantly. Wind strength and the relative position of other sailing craft may determine how frequently to tack. [16]

Tactics

A boat to windward of others enjoys undisturbed air, while disturbing the air for nearby boats that are downwind and behind. To keep this advantage the lead boat will often try to "cover" the trailing boat(s) by maneuvering to keep them "blanketed" in the disturbed air coming from its sails. The trailing boats seek to avoid the disturbed air from boats to windward without losing too much speed or momentum. [16] A "tacking duel" develops when a leading boat decides to cover a trailing boat and the trailing boat seeks to escape the disturbed air. A successful approach for the trailing boat is to tack within the area of maximally disturbed air, where the wind has the least effect on the boat's wind-caused drag (windage). [17] [18]

Roll tacking

Roll tacking, usually while racing sailing dinghies, involves aggressive heeling of the sailboat, as the skipper and crew move towards the windward side during the first half of the tack when the boat crosses through the wind. The skipper and crew then roll the boat back to an even keel following the completion of the tack, rapidly accelerating the boat back up to speed and allowing the sails to immediately resume their optimum shape on the new tack. [19] The form of the boat in the water, not the rudder, is the primary mechanism for changing course from one tack to the other. Some keel boats may also be roll tacked. [20]

See also

Related Research Articles

<span class="mw-page-title-main">Sailing</span> Propulsion of a vehicle by wind power

Sailing employs the wind—acting on sails, wingsails or kites—to propel a craft on the surface of the water, on ice (iceboat) or on land over a chosen course, which is often part of a larger plan of navigation.

<span class="mw-page-title-main">Sailing ship</span> Large wind-powered water vessel

A sailing ship is a sea-going vessel that uses sails mounted on masts to harness the power of wind and propel the vessel. There is a variety of sail plans that propel sailing ships, employing square-rigged or fore-and-aft sails. Some ships carry square sails on each mast—the brig and full-rigged ship, said to be "ship-rigged" when there are three or more masts. Others carry only fore-and-aft sails on each mast, for instance some schooners. Still others employ a combination of square and fore-and-aft sails, including the barque, barquentine, and brigantine.

<span class="mw-page-title-main">Rig (sailing)</span> Description of the specific ways that a sailing craft is rigged

A sailing vessel's rig is its arrangement of masts, sails and rigging. Examples include a schooner rig, cutter rig, junk rig, etc. A rig may be broadly categorized as "fore-and-aft", "square", or a combination of both. Within the fore-and-aft category there is a variety of triangular and quadrilateral sail shapes. Spars or battens may be used to help shape a given kind of sail. Each rig may be described with a sail plan—formally, a drawing of a vessel, viewed from the side.

A tack is a nautical term both for the lower, windward corner of a sail and, separately, for the windward side of a sailing craft (side from which the wind is coming while under way—the starboard or port tack. Generally, a boat is on a starboard tack if the wind is coming over the starboard side of boat with sails on port side. Similarly, a boat is on a port tack if the wind is coming over the port side of boat. However, confusion can result when a boat is on a 'run', with the wind coming directly from astern and the mainsail and jib/genoa are on opposite sides of the vessel. Therefore, the windward side is defined as the side opposite to that on which the mainsail is being carried. On a starboard tack the mainsail is carried on the port side. On a port tack the mainsail is carried on the starboard side. It is the position of the mainsail that determines the tack.

<span class="mw-page-title-main">Point of sail</span> Direction of travel under sail relative to true wind direction over surface

A point of sail is a sailing craft's direction of travel under sail in relation to the true wind direction over the surface.

<span class="mw-page-title-main">Jibe</span> Basic sailing maneuver, where ship turns its stern through the wind

A jibe (US) or gybe (Britain) is a sailing maneuver whereby a sailing vessel reaching downwind turns its stern through the wind, which then exerts its force from the opposite side of the vessel. Because the mainsail boom can swing across the cockpit quickly, jibes are potentially dangerous to person and rigging compared to tacking. Therefore, accidental jibes are to be avoided while the proper technique must be applied so as to control the maneuver. For square-rigged ships, this maneuver is called wearing ship.

<span class="mw-page-title-main">Spinnaker</span> Sail designed for sailing off the wind

A spinnaker is a sail designed specifically for sailing off the wind on courses between a reach to downwind. Spinnakers are constructed of lightweight fabric, usually nylon, and are often brightly colored. They may be designed to perform best as either a reaching or a running spinnaker, by the shaping of the panels and seams. They are attached at only three points and said to be flown.

<span class="mw-page-title-main">Gaff rig</span> Sailing rig configuration

Gaff rig is a sailing rig in which the sail is four-cornered, fore-and-aft rigged, controlled at its peak and, usually, its entire head by a spar (pole) called the gaff. Because of the size and shape of the sail, a gaff rig will have running backstays rather than permanent backstays.

<span class="mw-page-title-main">Lateen</span> Type of sailing rig

A lateen or latin-rig is a triangular sail set on a long yard mounted at an angle on the mast, and running in a fore-and-aft direction. The settee can be considered to be an associated type of the same overall category of sail.

<span class="mw-page-title-main">Running rigging</span> Lines that control sails

Running rigging is the rigging of a sailing vessel that is used for raising, lowering, shaping and controlling the sails on a sailing vessel—as opposed to the standing rigging, which supports the mast and bowsprit. Running rigging varies between vessels that are rigged fore and aft and those that are square-rigged.

<span class="mw-page-title-main">Full-rigged ship</span> Sailing vessel with three or more square-rigged masts

A full-rigged ship or fully rigged ship is a sailing vessel with a sail plan of three or more masts, all of them square-rigged. Such a vessel is said to have a ship rig or be ship-rigged, with each mast stepped in three segments: lower, top, and topgallant.

<span class="mw-page-title-main">Proa</span> Type of multihull sailboat

Proas are various types of multi-hull outrigger sailboats of the Austronesian peoples. The terms were used for native Austronesian ships in European records during the Colonial era indiscriminately, and thus can confusingly refer to the double-ended single-outrigger boats of Oceania, the double-outrigger boats of Island Southeast Asia, and sometimes ships with no outriggers or sails at all.

<span class="mw-page-title-main">Wingsail</span> Variable-camber aerodynamic structure

A wingsail, twin-skin sail or double skin sail is a variable-camber aerodynamic structure that is fitted to a marine vessel in place of conventional sails. Wingsails are analogous to airplane wings, except that they are designed to provide lift on either side to accommodate being on either tack. Whereas wings adjust camber with flaps, wingsails adjust camber with a flexible or jointed structure. Wingsails are typically mounted on an unstayed spar—often made of carbon fiber for lightness and strength. The geometry of wingsails provides more lift, and a better lift-to-drag ratio, than traditional sails. Wingsails are more complex and expensive than conventional sails.

Weather helm is the tendency of sailing vessels to turn towards the source of wind, creating an unbalanced helm that requires pulling the tiller to windward in order to counteract the effect.

<span class="mw-page-title-main">Forces on sails</span>

Forces on sails result from movement of air that interacts with sails and gives them motive power for sailing craft, including sailing ships, sailboats, windsurfers, ice boats, and sail-powered land vehicles. Similar principles in a rotating frame of reference apply to windmill sails and wind turbine blades, which are also wind-driven. They are differentiated from forces on wings, and propeller blades, the actions of which are not adjusted to the wind. Kites also power certain sailing craft, but do not employ a mast to support the airfoil and are beyond the scope of this article.

<span class="mw-page-title-main">Sail</span> Fabric or other surface supported by a mast to allow wind propulsion

A sail is a tensile structure, which is made from fabric or other membrane materials, that uses wind power to propel sailing craft, including sailing ships, sailboats, windsurfers, ice boats, and even sail-powered land vehicles. Sails may be made from a combination of woven materials—including canvas or polyester cloth, laminated membranes or bonded filaments, usually in a three- or four-sided shape.

<span class="mw-page-title-main">Kaep</span> Micronesian sailboat

Kaep is a traditional type of double-ended Proa sailboat native to Palau. Some of the essential design elements have also been adopted as a modern smaller multihull prototype variant.

<span class="mw-page-title-main">Lakana</span>

Lakana, also known as la'kana or laka, are traditional outrigger canoes of the Malagasy people of Madagascar. It is a single-outrigger canoe with a dugout main hull.

<span class="mw-page-title-main">Lug sail</span> Type of sail

The lug sail, or lugsail, is a fore-and-aft, four-cornered sail that is suspended from a spar, called a yard. When raised, the sail area overlaps the mast. For "standing lug" rigs, the sail may remain on the same side of the mast on both the port and starboard tacks. For "dipping lug" rigs, the sail is lowered partially or totally to be brought around to the leeward side of the mast in order to optimize the efficiency of the sail on both tacks.

<span class="mw-page-title-main">Wing and wing</span> Method of Sailing

Wing and wing, Wing on wing, Goosewinging or Goosewinged, is a term used to define, in a fore-and-aft-rigged sailboat, the way to navigate sailing directly downwind, with the mainsail and the foresail extended outwards on opposite sides of the boat, forming a 180º angle, to maximize the projected area of sail exposed to the wind. The jib is held out by the clew with a whisker pole, to allow the capture of the maximum amount of wind on the chosen side, without being covered by the mainsail.

References

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