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Centerboard
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; the term "centreboard" may refer to either a wooden or a metal pivoting retractable foil. 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 ... [...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; the term "centreboard" may refer to either a wooden or a metal pivoting retractable foil. 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 office ... [...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 two foresails, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sailboat
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 two foresails, 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 forw ... [...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] |
Foil (fluid Mechanics)
A foil is a solid object with a shape such that when placed in a moving fluid at a suitable angle of attack the lift (force generated perpendicular to the fluid flow) is substantially larger than the drag (force generated parallel to the fluid flow). If the fluid is a gas, the foil is called an airfoil or aerofoil, and if the fluid is water the foil is called a hydrofoil. Physics of foils A foil generates lift primarily because of its shape and angle of attack. When oriented at a suitable angle, the foil deflects the oncoming fluid, resulting in a force on the foil in the direction opposite to the deflection. This force can be resolved into two components: lift and drag. This "turning" of the fluid in the vicinity of the foil creates curved streamlines which results in lower pressure on one side and higher pressure on the other. This pressure difference is accompanied by a velocity difference, via Bernoulli's principle, so for foils generating lift the resulting flowfield ... [...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] |
Skeg
A skeg (or skegg or skag) is a sternward extension of the keel of boats and ships which have a rudder mounted on the centre line. The term also applies to the lowest point on an outboard motor or the outdrive of an inboard/outboard."A small fin fitted aft of the keel to protect the rudder and propeller, and improve steering and tracking." "Skeg, or Skegg. A projecting stump formerly left on the keel, abaft the stern-post. The after-end of the keel. The composition piece supporting the heel of an equipoise rudder." at Internet Archive In more recent years, the name has been used for a fin on a surfboard which improves directional stability and to a movable fin on a kayak which adjusts the boat's Center of lateral resistance, centre of lateral resistance (it moves the center of resistance relative to the center of effort). The term is also often used for the fin on water skis in the U.S. It has been used for the vertical fin on seaplane hulls and floats. The wear-bar on the bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leeboard
A leeboard is a form of pivoting keel used largely by sailboats, 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 inaccessible to fixed-keel boats. 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 leeboards typically ship (bear) little ballast, and being on the far ( lee) side delays the onset of unballasted craft's heeling, that is, inhibits the effect of putting up a good, constant resistance against the wind. The classical, archetypal definition of ballast is a low, central weight to optimise centre of mass, to reduce turning moment and therefore resistance to the boat keeling over; however, the centre of gravity tends to be higher in self-righting vessels. Modern developments allow leeboards to act as a speed-enh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinghy Racing
Dinghy racing is a competitive sport using dinghies, which are small boats which may be rowboats, have an outboard motor, or be sailing dinghies. Dinghy racing has affected aspects of the modern sailing dinghy, including hull design, sail materials and sailplan, and techniques such as planing and trapezing. Organization of competitive dinghy sailing Dinghy racing comes under the auspices of World Sailing. Organisations such as the Royal Yachting Association, National School Sailing Association (UK) and Canadian Yachting Association (Canada) organise and regulate the sport at a national level. Sailing dinghies compete on an international, national, state, association, club and class basis, using the ISAF International Racing Rules of Sailing, which are revised every four years. There are several courses used, such as the Olympic triangle. The International Association for Disabled Sailing (IFDS) is the body authorized by ISAF to be responsible for disabled sailing worl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinghy
A dinghy is a type of small boat, often carried or Towing, towed by a Watercraft, larger vessel for use as a Ship's tender, tender. Utility dinghies are usually rowboats or have an outboard motor. Some are rigged for sailing but they differ from Dinghy sailing, 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 (maritime), 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 language, Bengali ', Urdu ', and Hindi '. Definition and basic description The term "dinghy" has some variability in its definition, but is generally a small open boat which may be powered by oars, sail or an outboard motor. Some individual examples have the option of being p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bilgeboard
A bilgeboard is a lifting foil used in a sailboat, which resembles a cross between a centerboard and a leeboard. Bilgeboards are mounted between the centerline of the boat and the sides, and are almost always asymmetric foils mounted at an angle to maximize lateral lift while minimizing drag. They are most often found on racing scows. When sailing, the windward side bilgeboard is retracted into the hull of the boat, so that it produces no drag. The leeward side foil provides the lift to counter the lateral force of the sail, and converts it into forward motion. The bilgeboards are angled so that as the boat heels, or leans under the force of the wind, the leeward bilgeboard becomes more upright, and provides the greatest possible force in the desired direction. Like a centerboard, the bilgeboard can be used as a recovery platform upon which to stand in the event the dinghy overturns via a capsize or turtle. The ''Red Fox'' is a modern cruising yacht that uses bilgeboards to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
