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Centreboard
A centreboard or centerboard (US) is a retractable hull appendage which pivots out of a slot in the hull of a sailboat, known as a ''centreboard trunk'' (UK) or ''centerboard case'' (US). The retractability allows the centreboard to be raised to operate in shallow waters, to move the centre of lateral resistance (offsetting changes to the sailplan that move the centre of effort aft), to reduce drag when the full area of the centreboard is not needed, or when removing the boat from the water, as when trailering. A centreboard which consists of solely a pivoting metal plate is called a centerplate. A daggerboard is similar but slides vertically rather than pivoting. The analog in a scow is a bilgeboard: these are fitted in pairs and used one at a time. General History Lt. John Schank (c. 1740 – 6 February 1823) was an officer of the British Royal Navy and is credited with the invention of the centerboard. Schank, however, gave credit for the idea to British Brigadier General ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centerboard (PSF)
A centreboard or centerboard (US) is a retractable Hull_(watercraft)#Appendages, hull appendage which pivots out of a slot in the hull (watercraft), hull of a sailboat, known as a ''centreboard trunk'' (UK) or ''centerboard case'' (US). The retractability allows the centreboard to be raised to operate in shallow waters, to move the centre of lateral resistance (offsetting changes to the sailplan that move the centre of effort aft), to reduce drag when the full area of the centreboard is not needed, or when removing the boat from the water, as when Trailer (vehicle), trailering. A centreboard which consists of solely a pivoting metal plate is called a centerplate. A daggerboard is similar but slides vertically rather than pivoting. The analog in a scow is a bilgeboard: these are fitted in pairs and used one at a time. General History Lt. John Schank (c. 1740 – 6 February 1823) was an officer of the British Royal Navy and is credited with the invention of the centerboard. Schank ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leeboard
A leeboard is a form of pivoting keel used by a sailboat largely and very often in lieu of a fixed keel. Typically mounted in pairs on each side of a hull, leeboards function much like a centreboard, allowing shallow-draft craft to ply waters fixed keel boats cannot. Only the leeward side leeboard is used at any time, as it submerges when the boat heels under the force of the wind. A disadvantage, where there is an inadequate fixed keel, is that they typically ship (bear) little ballast, which being on the far side delays the onset of unballasted craft's heeling, that is, to put up a good, constant resistance against the wind. The classical, archetypal definition of ballast is a low, central weight to optimise centre of mass, reduce turning moment and therefore resistance to the boat keeling over, however tends to be higher in self-righting vessels. Modern developments allow them to act as a speed-enhancing lifting foil. History Leeboards existed in China from at least the e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hull (watercraft)
A hull is the watertight body of a ship, boat, or flying boat. The hull may open at the top (such as a dinghy), or it may be fully or partially covered with a deck. Atop the deck may be a deckhouse and other superstructures, such as a funnel, derrick, or mast. The line where the hull meets the water surface is called the waterline. General features There is a wide variety of hull types that are chosen for suitability for different usages, the hull shape being dependent upon the needs of the design. Shapes range from a nearly perfect box in the case of scow barges to a needle-sharp surface of revolution in the case of a racing multihull sailboat. The shape is chosen to strike a balance between cost, hydrostatic considerations (accommodation, load carrying, and stability), hydrodynamics (speed, power requirements, and motion and behavior in a seaway) and special considerations for the ship's role, such as the rounded bow of an icebreaker or the flat bottom of a landing craft. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hull (watercraft)
A hull is the watertight body of a ship, boat, or flying boat. The hull may open at the top (such as a dinghy), or it may be fully or partially covered with a deck. Atop the deck may be a deckhouse and other superstructures, such as a funnel, derrick, or mast. The line where the hull meets the water surface is called the waterline. General features There is a wide variety of hull types that are chosen for suitability for different usages, the hull shape being dependent upon the needs of the design. Shapes range from a nearly perfect box in the case of scow barges to a needle-sharp surface of revolution in the case of a racing multihull sailboat. The shape is chosen to strike a balance between cost, hydrostatic considerations (accommodation, load carrying, and stability), hydrodynamics (speed, power requirements, and motion and behavior in a seaway) and special considerations for the ship's role, such as the rounded bow of an icebreaker or the flat bottom of a landing craft. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daggerboard
A daggerboard is a retractable centreboard used by various sailing craft. While other types of centreboard may pivot to retract, a daggerboard slides in a casing. The shape of the daggerboard converts the forward motion into a windward lift, countering the leeward push of the sail. The theoretical centre of lateral resistance is on the trailing edge of the daggerboard. General A daggerboard is a removable vertical keel that is inserted through a "trunk" in the center of a vessel's hull, usually amidships. Daggerboards are usually found in small sailing craft such as day sailers, which are easily handled by a single person. Daggerboards are not usually ballasted but are locked in place by a clip or pin. Unlike a centreboard, which can be set at different angles to the hull of the boat, daggerboards are generally limited to a single perpendicular position relative to the hull. If a daggerboard is located off center, it is called a leeboard or a bilgeboard. The characteristic whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daggerboard
A daggerboard is a retractable centreboard used by various sailing craft. While other types of centreboard may pivot to retract, a daggerboard slides in a casing. The shape of the daggerboard converts the forward motion into a windward lift, countering the leeward push of the sail. The theoretical centre of lateral resistance is on the trailing edge of the daggerboard. General A daggerboard is a removable vertical keel that is inserted through a "trunk" in the center of a vessel's hull, usually amidships. Daggerboards are usually found in small sailing craft such as day sailers, which are easily handled by a single person. Daggerboards are not usually ballasted but are locked in place by a clip or pin. Unlike a centreboard, which can be set at different angles to the hull of the boat, daggerboards are generally limited to a single perpendicular position relative to the hull. If a daggerboard is located off center, it is called a leeboard or a bilgeboard. The characteristic whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinghy Sailing
Dinghy sailing is the activity of sailing small boats by using five essential controls: * the sails * the foils (i.e. the daggerboard or centreboard and rudder and sometimes lifting foils as found on the Moth) * the trim (forward/rear angle of the boat in the water) * side-to-side balance of the dinghy by hiking or movement of the crew, particularly in windy weather ("move fast or swim") * the choice of route (in terms of existing and anticipated wind shifts, possible obstacles, other water traffic, currents, tides etc.) When racing, the above skills need to be refined and additional skills and techniques learned, such as the application of the "racing rules of sailing", boat handling skills when starting and when rounding marks, and knowledge of tactics and strategy. Racing tactics include positioning the boat at different angles. To improve speed when racing, sailors should position themselves at the windward direction (closest to the direction of the wind) in order to get " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
:en:Randmeer
The Randmeer is a medium size sailing boat designed by E.G. van de Stadt. In the Netherlands it is often used for One-Design sailing races. Developed in the 1960s it was made especially for sailing on the so-called '' randmeren''; narrow shallow lakes that surround the newly created Flevopolders. This makes the boat perfect for rough but shallow waters. Size The ''Randmeer'' is 6.50 meters long and 2.10 meters wide. The hull weighs 500 kilograms. The draft can vary, depending on whether it has a centreboard, between 0.55 and 1.15 meters. The mainsail has a surface area of 11.4 m2, the jib has a surface area of 7.7 m2. The 'Touring' type has a jib of 5.6 m2. In addition it can be sailed with a spinnaker of 19.5 m2. All boats are produced at the shipyard in Heeg, Friesland, The Netherlands. Types Within the Randmeer class there are three types: the ''Classic''; the ''Advance''; and the ''Touring''. The Classic, as can inferred from the name, is the original design that dates b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinghy
A dinghy is a type of small boat, often carried or towed by a larger vessel for use as a tender. Utility dinghies are usually rowboats or have an outboard motor. Some are rigged for sailing but they differ from sailing dinghies, which are designed first and foremost for sailing. A dinghy's main use is for transfers from larger boats, especially when the larger boat cannot dock at a suitably-sized port or marina. The term "dinghy towing" sometimes is used to refer to the practice of towing a car or other smaller vehicle behind a motorhome, by analogy to towing a dinghy behind a yacht. Etymology The term is a loanword from the Bengali ', Urdu ', and Hindi '. Types Dinghies usually range in length from about . Larger auxiliary vessels are generally called tenders, pinnaces or lifeboats. Folding and take-down multi-piece (nesting) dinghies are used where space is limited. Some newer dinghies have much greater buoyancy, giving them more carrying capacity than older ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scow
A scow is a smaller type of barge. Some scows are rigged as sailing scows. In the 19th and early 20th centuries, scows carried cargo in coastal waters and inland waterways, having an advantage for navigating shallow water or small harbours. Scows were in common use in the American Great Lakes and other parts of the U.S., Canada, southern England, and New Zealand. In modern times their main purpose is for recreation and racing. Scows The name "scow" derives from the Dutch , ultimately from the German for a punt pole and subsequently transferred to mean the boat. Old Saxon has a similar word which means to push from the shore, clearly related to punting. The basic scow was developed as a flat-bottomed barge ( a large punt) capable of navigating shallow rivers and sitting comfortably on the bottom when the tide was out. By 1848 scows were being rigged for sailing using leeboards or sliding keels. They were also used as dumb barges towed by steamers. Dumb scows were used for a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sailboat Components
A sailboat or sailing boat is a boat propelled partly or entirely by sails and is smaller than a sailing ship. Distinctions in what constitutes a sailing boat and ship vary by region and maritime culture. Types Although sailboat terminology has varied across history, many terms have specific meanings in the context of modern yachting. A great number of sailboat-types may be distinguished by size, hull configuration, keel type, purpose, number and configuration of masts, and sail plan. Popular monohull designs include: Cutter The cutter is similar to a sloop with a single mast and mainsail, but generally carries the mast further aft to allow for a jib and staysail to be attached to the head stay and inner forestay, respectively. Once a common racing configuration, today it gives versatility to cruising boats, especially in allowing a small staysail to be flown from the inner stay in high winds. Catboat A catboat has a single mast mounted far forward and does not carr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capsizing
Capsizing or keeling over occurs when a boat or ship is rolled on its side or further by wave action, instability or wind force beyond the angle of positive static stability or it is upside down in the water. The act of recovering a vessel from a capsize is called righting. Capsize may result from broaching, , loss of stability due to cargo shifting or flooding, or in high speed boats, from turning too fast. If a capsized vessel has enough flotation to prevent sinking, it may recover on its own in changing conditions or through mechanical work if it is not stable inverted. Vessels of this design are called self-righting. Small vessels In dinghy sailing, a practical distinction can be made between being knocked down (to 90 degrees; on its beam-ends, figuratively) which is called a capsize, and being inverted, which is called being turtled. Small dinghies frequently capsize in the normal course of use and can usually be recovered by the crew. Some types of dinghy are occasi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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