The points of sail clarify the realities of sailing into the wind. One of the points of sail is "head to wind". A boat turns through that point on each tack. It is the point at which the boat is neither on port tack or starboard tack and is headed directly into the wind.
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Three sail shape controls which control the leech tension, and therefore sail twist, are the mainsheet, the boom vang and the traveler. The mainsheet pulls the boom (and therefore the foot of the sail) primarily inwards at lower points of sail and downwards at higher points of sail. Manipulation of the traveler can counteract this because it always pulls the boom laterally. The vang on the other hand does the opposite, it always changes the height of the boom.
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The highest speed for most sailboats is reaching with the wind from the side or the aft quarter (a beam reach or a broad reach).Points of Sail , SchoolofSailing.net, Burlington, VT USA. Viewed Dec.
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18ft Skiff in Kiel Harbor High-performance sailing is achieved with low forward surface resistance—encountered by catamarans, sailing hydrofoils, iceboats or land sailing craft—as the sailing craft obtains motive power with its sails or aerofoils at speeds that are often faster than the wind on both upwind and downwind points of sail. Faster-than-the-wind sailing means that the apparent wind angle experienced on the moving craft is always ahead of the sail. This has generated a new concept of sailing, called "apparent wind sailing", which entails a new skill set for its practitioners, including tacking on downwind points of sail.
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Sails may be classified as either triangular, which describes sails that either come to one point of suspension at the top or where the sail comes to a point at the forward end, or quadrilateral, which includes sails that are attached to a spar at the top and have three other sides, or as square. They also may be classified as symmetrical (square sails and symmetric spinnakers) or asymmetrical (most other sails). Typically, asymmetrical sails perform better on points of sail closer to the wind than symmetrical sails and are designed for fore-and-aft rigs. Symmetrical sails perform best on points of sail that are further from the wind direction.
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Sail-powered vehicles travel over land or ice at apparent wind speeds that are higher than the true wind speed, close-hauled on most points of sail. Both land yachts and ice boats have low forward resistance to speed and high lateral resistance to sideways motion.
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The furling sails are stored in the mast and can be deployed along tracks on the yards in six minutes. The sails are trimmed by rotating the masts. As there is no rigging, the masts and yards can be rotated without restriction for all points of sail, making Black Pearl a capable upwind clipper.
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Points of sail with a kite buggy. Current kite rigs can be sailed within 50 degrees of the wind.Skysails, Captain John Konrad, Mariner's Weather Log, April 2009, Volume 53, No. 1, National Weather Service This allows them to sail upwind by tacking. A power kite is held at an angle to the wind using control lines.
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Diagram of apparent wind (VA) on an iceboat on different points of sail Iceboats designs dating from the mid 20th century onwards typically consist of a triangular or cross-shaped frame, supported by three skate blades called "runners", with the steering runner in front. Runners are made of iron or steel with sharpened edges, which hold onto the ice, preventing slippage sideways from the lateral force of the wind developed by the sails, as they develop propulsive lift. Given their low forward resistance, iceboats can sail up to five times the speed of the true wind. Because the velocity of the iceboat (VB) is so much greater than the true wind velocity (VT), the apparent wind (VA) is only a few degrees from the direction of travel on most points of sail and the sail is close-hauled in each.
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Aigue Blu raising her spinnaker during the ‘Corsica Classic 2013’ yacht race Since they will only be used on certain points of sail, raising and lowering the spinnaker is a task that is often performed while under sail. Due to the size of spinnakers (the spinnaker is often double or more the size of the mainsail) this can be a difficult operation, since the sail will immediately catch the wind.
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A Ljungström rig usually has two sails, stitched together at the luff. On all points of sail, except a full run, these sails are close together. In the unlikely event that one of the sails would rip the other still stands and the boat can safely reach harbor. The Ljungström rig is often compared with a staysail with the big difference that the mast bends inversely to the forestay.
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Because wind-powered vehicles typically sail at apparent wind angles aligned with the leading edge of the sail, the sail acts as an airfoil and lift is the predominant component of propulsion. Low forward resistance to motion, high speeds over the surface, and high lateral resistance help create high apparent wind speeds—with closer alignment of the apparent wind to the course traveled for most points of sail—and allow wind-powered vehicles to achieve higher speeds than conventional sailing craft.
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Racing yachts have a wide selection of weights and shapes of sail to accommodate different wind strengths and points of sail. A suite of sails on a racing yachts would include several weights of jib and spinnaker, plus a specialized storm jib and trysail (in place of the mainsail). Performance yachts are likely to have full-battened kevlar or carbon-fiber mainsails. Underwater foils can become more specialized, starting with a higher-aspect ratio fin keel with hydrodynamically efficient bulbs for ballast.
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Gitana 13, an ocean-racing catamaran Recreational and sport catamarans typically are designed to have a crew of two and be launched and landed from a beach. Most have a trampoline on the bridging structure, a rotating mast and full-length battens on the mainsail. Performance versions often have trapezes to allow the crew to hike out and counterbalance capsize forces during strong winds on certain points of sail. For the 33rd America's Cup, both the defender and the challenger built long multihulls.
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Front loops may be initiated, unhooked, from close-hauled through broad-reach points of sail, with ease of initiation often determined by wave-face rather than wind direction. To properly position the center of effort, the rider typically moves their body from a windward sailing position to a position toward the back and centerline of the board. The forward leg will often be straightened—the rear leg bent. To achieve this position, the sail will have been sheeted out slightly during the motion.
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High-performance rigs provide aerodynamic efficiency and hydrodynamically efficient hulls minimize drag through the water and sideways motion. Racing yachts have a wide selection of weights and shapes of sail to accommodate different wind strengths and points of sail. A suite of sails on a racing yachts would include several weights of jib and spinnaker, plus a specialized storm jib and trysail (in place of the mainsail). Performance yachts are likely to have full-battened kevlar or carbon-fiber mainsails.
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As the sail lowers by its own weight, the other running lines will also relax. The sail is lowered until the desired batten is along the boom. Then the gaff hauling parrel and luff hauling parrel are trimmed, and the sheet is hauled to reset the sail to the wind. When reefing on other points of sail, it is helpful to ease the sheet first to take the pressure off the sail, and then ease the halyard and trim the other running lines.
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Sailors use this term synonymously with the points of sail below a beam reach, since the wind direction is generally the same as the sea direction. Therefore, the phrase "Fair winds and following seas," implies that a vessel will have good winds, and not have to pound into the waves. The phrase is now used as a popular toast or salutation between mariners. It is also used during ceremonies, such as the beginning of a voyage, a ship's commissioning, a retirement, funeral et cetera.
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Some users (such as in the Royal Navy Montagu whaler) would still dip the yard of a standing lug (with a sharp, well timed downward pull on the leech at the moment when the wind is not filling the sail). Conversely many fishermen would always hoist a standing lug on the same side of the mast regardless of which tack they expected to be sailing on. Sailing performance with a standing lug relies on the right amount of luff tension. An essential component of this rig is the tack tackle, a purchase with which luff tension is adjusted for various points of sail.
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Examples of drag include the component of the net aerodynamic or hydrodynamic force acting opposite to the direction of movement of a solid object such as cars, aircraft and boat hulls; or acting in the same geographical direction of motion as the solid, as for sails attached to a down wind sail boat, or in intermediate directions on a sail depending on points of sail. In the case of viscous drag of fluid in a pipe, drag force on the immobile pipe decreases fluid velocity relative to the pipe. In the physics of sports, the drag force is necessary to explain the performance of runners, particularly of sprinters.
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Angle of attack is often constrained by the sailing craft's orientation to the wind or point of sail. On points of sail where it is possible to align the leading edge of the sail with the apparent wind, the sail may act as an airfoil, generating propulsive force as air passes along its surface—just as an airplane wing generates lift—which predominates over aerodynamic drag retarding forward motion. The more that the angle of attack diverges from the apparent wind as a sailing craft turns downwind, the more drag increases and lift decreases as propulsive forces, until a sail going downwind is predominated by drag forces. Sails are unable to generate propulsive force if they are aligned too closely to the wind.
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The points of sail at which high-performance sailing craft can achieve highest speeds and achieve the best speed made good over a course span between a beam reach (90° to the true wind) and a broad reach (about 135° away from the true wind). According to Bethwaite, having made comparative measurements in a true wind of , a displacement Soling can achieve speeds slightly higher than the true wind and sail 30° off the apparent wind, whereas a planing 18-foot Skiff achieves speeds of almost at an apparent wind of 20° and an iceboat can achieve at an apparent wind of 8°. Under apparent wind sailing, the objective is to keep the apparent wind as far forward, as practical, for the course sailed in order to attain the fastest course made good to the objective. This requires a craft that can exceed the true windspeed, both upwind and downwind; this allows the apparent wind to remain well ahead of the sail on the courses sailed, the fastest of which are reaches.
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