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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; 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 inventio ... [...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] |
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] |
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] |
Hull (watercraft)
A hull is the watertight body of a ship, boat, submarine, 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 (sailing), 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 bot ... [...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] |
Keel
The keel is the bottom-most longitudinal structural element of a watercraft, important for stability. On some sailboats, it may have a fluid dynamics, hydrodynamic and counterbalancing purpose as well. The keel laying, laying of the keel is often the initial step in constructing a ship. In the British and American shipbuilding traditions, this event marks the beginning date of a ship's construction. Etymology The word "keel" comes from Old English language, Old English , Old Norse , = "ship" or "keel". It has the distinction of being regarded by some scholars as the first word in the English language recorded in writing, having been recorded by Gildas in his 6th century Latin work ''De Excidio et Conquestu Britanniae'', under the spelling ''cyulae'' (he was referring to the three ships that the Saxons first arrived in). is the Latin word for "keel" and is the origin of the term careening, careen (to clean a keel and the hull in general, often by rolling the ship on its side). An ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinghy Sailing
Dinghy sailing is the activity of sailing small boats - usually for fun, learning necessary sailing skills (often also within family), and competition. RYA lists Five essentials of sailing dinghies as: * 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, ... [...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 while 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 ar ... [...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] |
