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.[ citation needed ]
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 which differentiates daggerboards from other centerboards and swing keels is that daggerboards are easily removable, even when the boat is underway. Centerboards and swing keels, common alternatives to fixed keels, can pivot up and down but are fixed to the hull. The freedom of movement of dagger- and centerboards allows them to swing or slide up into the hull of the boat, which is advantageous when sailing in shallow waters. The pivoting centerboard or swing keel can swing up when it strikes an object which helps prevents the sort of damage to which fixed keels or daggerboards are subject. [1] Daggerboards can be raised and lowered as needed but will generally be damaged if not retracted before impact with the bottom or with floating objects.
Many small sailboats use a daggerboard instead of a fixed keel. This allows these boats to be more easily moved on trailers, sailed in shallow waters, and easily beached. [2] Daggerboards also afford an opportunity to reduce drag when racing because they can be retracted when not needed (i.e. when sailing downwind or in very light winds).
Daggerboards are often made of wood; the problem with wood is that wood rots over time. Alternate materials for daggerboards are metal (aluminum/steel) and fiberglass. A daggerboard boat can be costly to manufacture. If not well-made, the daggerboard will transfer vibrations from the trunk through the hull.
The purpose of the daggerboard (or any keel) is to balance the force of the wind on the sails. Without a daggerboard or keel, a sailboat could not sail up-wind and would simply be blown sideways. [1]
During a storm, daggerboards can help reduce the tendency of a small boat to tip over ("breach") due to waves. A catamaran in a storm would lift the leeward hull daggerboard and fully extend the upwind daggerboard.[ citation needed ] If there is no wind and an outboard motor is being used, lifting the daggerboards will ensure the least drag. [3]
When a small sailboat flips on its side, the keel can also be used to right the boat. Standing on the keel gives the sailor additional leverage to roll the hull upright. The centerboard, daggerboard, or bilgeboard can be used as a platform upon which to stand, providing increased leverage, in the event the dinghy overturns via a capsize or turtle.
Because water is denser than air, the force generated by wind against the much larger surface area of the sails can be equalized by the force of a relatively small daggerboard pushing in the water below the hull. A daggerboard fits into a trunk that runs through the hull of the rig. When the board is in the trunk it keeps the water out while in use due to how tightly wedged it is. It is held in place by a pin on the forward end or a shock cord. The daggerboard puts a counterforce from the wind pushing on the sails. Daggerboards are often long and thin to reduce drag and increase effective lift, thus providing a better lift-to-drag ratio.
In 2008, a 55-foot-long (17 m) daggerboard ship was found using deep scan sonar equipment off the southern shore of Lake Ontario, the only such vessel known to have been found in the Great Lakes. Vessels of this type were used for a short time in the early 19th century. [2]
In the early 19th century daggerboards were infrequently being used on American schooners. These schooners were used for nearby coastal trade of cotton, wheat, and apples. A sunken 1833 daggerboard schooner was found in the great lakes with the help of sonar equipment. [4] Knowing this, daggerboards have been around since late in the 17th century. Daggerboards can be found on monohulls which is the classic sailboat and multihulls called catamarans.
Daggerboards come in all different shapes and sizes, some curved or s-shaped. Curved daggerboards started to appear thirty to forty years ago. The first prototype was made in 1985 by Ian Farrier. The benefits of vertical lift generated by curved daggerboards are nominal. When actually sailing, curved daggerboards - not to be confused with hydrofoils - do not make a drastic change. [5]
Generally, daggerboards are used on smaller rigs such as 10 to 40 feet for racing but there is a large number of custom and semi-custom catamaran builders who offer daggerboards as an option. Daggerboard rigs may be faster than fixed keels because fixed keels have so much hydrodynamic drag by the shape. Some makes which utilize a daggerboard design are: The Mirror Dinghy, Laser, Vanguard 15. [6]
A hull is the watertight body of a ship, boat, submarine, or flying boat. The hull may open at the top, 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.
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.
The keel is the bottom-most longitudinal structural element on a watercraft. On some sailboats, it may have a hydrodynamic and counterbalancing purpose, as well. The laying of the keel is often the initial step in the construction of a ship. In the British and American shipbuilding traditions, this event marks the beginning date of a ship's construction.
Dinghy sailing is the activity of sailing small boats by using five essential controls:
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, 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.
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 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.
Hobie Cat is a company that manufactures watercraft and other products as the Hobie Cat Company. "Hobie Cat" can also refer to specific products of the company, notably its sailing catamarans. Its fiberglass catamaran models range in nominal length between 14 feet (4.3 m) and 18 feet (5.5 m). Rotomolded catamaran models range in length between 12 feet (3.7 m) and 17 feet (5.2 m). Other sailing vessels in the Hobie Cat lineup include, monocats, dinghies, and trimarans, ranging in length between 9 feet (2.7 m) and 20 feet (6.1 m). Its largest product was the Hobie 33, 33 feet (10 m) in length. The company's non-sailing product line includes surfboards, kayaks, stand-up paddle boards, pedalboards, eyeware, and e-bikes. It was founded in 1961 by Hobart (Hobie) Alter, who originally manufactured surfboards.
The MacGregor Yacht Corporation was a manufacturer of sailing yachts, located in Costa Mesa, California.
A sailing hydrofoil, hydrofoil sailboat, or hydrosail is a sailboat with wing-like foils mounted under the hull. As the craft increases its speed the hydrofoils lift the hull up and out of the water, greatly reducing wetted area, resulting in decreased drag and increased speed. A sailing hydrofoil can achieve speeds exceeding double and in some cases triple the wind speed.
A trailer sailer is a type of sailboat that has been designed to be easily transported using a boat trailer towed by an automobile. They are generally larger than a sailing dinghy. Trailer sailers include day sailers and small cabin cruisers, suitable for living on.
The following outline is provided as an overview of and topical guide to sailing:
The Beachcomber 25 is an American trailerable sailboat that was designed by Walter Scott as a cruiser and first built in 1979.
The Stiletto 27 is an American trailerable catamaran sailboat that was designed by Bill Higgins and Don Ansley as a racer/cruiser and first built in 1976.
The Cheshire 14 is an American catamaran sailing dinghy that was designed by Frank Meldau as a racer and first built in 1962.
The Phantom 14, also called the Phantom 14', is an Italian catamaran sailing dinghy that was first built in 1995.
The Phantom 16, also called the Phantom 16', is an Italian catamaran sailing dinghy that was first built in 1988.
The G-Cat 5.0 is an American catamaran sailing dinghy that was designed by Hans Geissler as a one-design racer and first built in 1975.
The G-Cat 5.7 is an American catamaran sailing dinghy that was designed by Hans Geissler as a one-design racer and first built in 1980.
The Poacher 21, also called the Parker Dawson Poacher, is an American trailerable sailboat that was designed by W. Richardson as a racer-cruiser and first built in 1980.
