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Boat building, one of the oldest branches of engineering, is concerned with constructing the hulls of boats and, for sailboats, the masts, spars and rigging. ==Parts== *Anchor- a heavy, pick like device, attached to a boat's stem by a warp and chain. Common types are Plow or Fisherman and Danforth. Modern anchors are made of steel but in pre-industrial societies rocks were used. The chain is added to the lower anchor end to add weight and prevent chafing of the rope warp on rocks or shellfish beds. *Angel also virgin or maiden. A Norsemen invention used in sailing long ships from about the 10th century AD that predates blocks. They served the purpose of a block/jamb cleat in one unit. It was a flat section of wood about 150 high x 120 wide shaped like an angel/butterfly used in attaching stays to the hull. The V-shape at the lower part of the "wings" acted as a V jam cleat. *Bitts - Two short strong posts often made of steel, located on the fore and aft side decks of a heavily built boat or ship, that are designed to take heavy mooring lines. *Bilge - the lowest part of the hull interior, under the sole. Often water and or fuel tanks are placed in the bilges to lower the centre of gravity. *Bilge keel - a longitudinal, external, underwater member used to reduce a ship's tendency to roll. In Britain twin bilge keels are often used on small boats moored in estuaries with a large tidal range so the boat stay upright when dried out. With their much shallower draft yachts of this type can be sailed in shallow waters. Not as hydro dynamically efficient as a fin keel. *Bilge pump - a pump, either manual or electric with the inlet set at the lowest point in the bilges where water will collect when the boat is upright. The inlet is protected by a screen to stop blockages *Block a fitting with a circular wheel inside 2 cheeks designed to hold the turn of a rope. Originally made of wood, they are now made of plastic, stainless steel or carbon fibre. They are mainly used in rigging in pairs or quads to allow a single person to operate a sail that creates a lot of force. Similar to a pulley or sheave. *Bow - The front and generally sharp end of the hull. It is designed to reduce the resistance of the hull cutting through water and should be tall enough to prevent water from easily washing over the deck of the hull. *Bowsprit - A spar that extends forward from the foredeck, outboard of the hull proper. Common in square rigged ships where they were used to attach the outer or flying jib. In modern sailboats they are often made of lightweight carbon and used for attaching the luff of lightweight down-wind sails. *Breasthook - A roughly triangular piece of wood fitted immediately aft of the stem and between the two inwales or sheer clamps usually in a wooden dinghy. *Bulkhead - The internal transverse walls of the hull. *Bulwarks - The upstanding part of the topsides, above the deck, providing safe footing when a boat is heeled. *Cam cleat- a mechanical cleat with 2 spring-loaded cam jaws, usually made of hard plastic, that clamp onto a sheet. The sheet can be easily pulled forward and upwards to release it but is held tight in the cam jaws when unattended. *Catsheads - A short timber(or pair of timbers) that protrudes approximately at right angles from the foredeck of a square rigged sailing ship. Its purpose is to support the weight of the anchor and keep the anchor secure and outboard of the hull to avoid damaging the hull planking. *Capstan A vertical metal or wooden winch secured to the foredeck of a ship, used for hoisting the anchor. Capstans may be manually operated or powered hydraulically or electrically. A traditional wooden capstan is fitted with removable wooden arms fitted into sockets on which the seaman push. Seashanties were often chanted to keep the seamen together as they pushed. *Carlin - A longitudinal strip parallel to, but inboard of, the inwale (sheer clamp). It supports the inboard edge of the side deck and the side of the cabin cladding. *Chainplate - A strip of strong metal, often stainless steel, through-bolted to the topsides and a frame and protruding above deck level to take the load of a stay in a sail boat. *Centre board - (also dagger board) an elongated underwater appendage that fits vertically in the slot of a centre case and extends below the hull. It can be retracted so the boat can float in very shallow water. The board has a length to breadth ratio of about 4;1. The board is tapered to a hydrodynamic (teardrop) shape in plan section to promote laminar flow of the water. This shape prevents stalling or eddying when sailing to windward. Together with the sails it lifts the hull in the windward direction. Common materials are wood often reinforced with fibreglass or carbon to obtain more stiffness and abrasion resistance. When sailing to windward the board is fully down but is retracted about half way when sailing directly down wind. When sailing to windward an efficient board prevents most leeway (sideways movement). * Chines - Are the abrupt change of angle where the topside meets the bottom of a hull. In a power or fast sail boat boat the chine deflect spray down wards when the hull is travelling at speed. A multi chine hull has 4 or more chines to allow an approximation of a round bottomed shape using flat panels. It also refers to the longitudinal structural members inside the hull which support the edges of these panels. Traditionally these were called chine logs especially in Eastern USA. *Cleat - A fitting designed to tie off ropes. Often T shaped. *Coaming - any vertical surface on a ship designed to deflect or prevent entry of water *Cockpit - The seating area towards the stern of a small decked vessel where the rudder controls are located. *Counter stern - a traditional stern construction with a long overhang and a shorter, upright, end piece. The stern is rounded when in plan-view. The counter is usually decked over. *Companion way-in a small yacht this is the short ladder that leads from the cockpit to cabin or saloon. Often it is detachable for access to the engine or storage. In a large vessel it is a permanent ladder between decks. A companion way usually has non slip treads and handholds. *Crosstree- two short metal arms that are attached to a mast athwartwise about mid height. Mast side stays are tensioned by running through the outboard end of the arms, often forming a diamond shape. Similar to a spreader. *Deck - The top surface of the hull keeps water and weather out of the hull and allows the crew to operate the boat more easily. It stiffens the hull. Temporary frames (or moulds) can be removed and kept for another boat. *Deck beam - A heavy timber running athwartwise(across)from the top of a frame under the deck. It usually has a gentle convex (upward) curve for extra strength, extra head height below deck along the centre line and to allow water to run off the deck when the boat is upright. *Dolphin striker - A short spar fitted mid-way and vertically downwards, midway along a bowsprit that holds the bobstay and prevents the outboard end of the bowsprit riding upwards under the load of a tensioned headsail. *Dorade - A ventilation intake consisting of a cowling connected to a short vertical tube connected to a deck mounted scuppered (Dorade) box, usually made from teak. The cabin intake is offset to prevent water entering the cabin. The upper section swivels to stop breaking seas entering the dorade. Named after the 1931 yacht Dorade where it was first used. *Epoxy resin -a chemical fluid widely used in advanced wooden boat building since the 1980s in a variety of forms, principally glue, as a filler (with a variety of powders or sawdust) and as a moisture-resistant barrier on both the interior and exterior of a wooden hull. The method was popularized by the WEST system. Sometimes used in conjunction with various cloths such as fibreglass, kevlar or carbon fibre. A thinned mixture of resin is used to penetrate the fibres of light weight woods such as Balsa and Western red cedar forming a waterproof barrier, far superior to single pot paint or varnish. In small boat and kayak construction Epoxy resin is often used in conjunction with lightweight 3 or 4 mm thick Okoume (Gaboon) plywood to form very light strong hulls. Typically few nails or screws are needed as the resin is so strong. Slow drying and far stronger but more difficult to sand than polyester resin. Typically applied with a roller, throw away brushes and radiused flat tongue depressor for coving using thickened epoxy. Softens and weakens slightly at high ambient temperatures so vessels in tropical waters should be lighter coloured. *Fairlead-A U-shape or circular fitting often positioned near the bow that leads an anchor warp or a sheet to a cleat or winch. The anchor fairlead is usually bronze or stainless steel as it must take the regular abrasion of the warp and chain. The anchor fairlead is usually set on the change of angle between the deck and the topside to prevent wear and tear. *Fiddle-or fiddle rail. A low rail about 40 mm high, either of solid wood or lathe-turned fiddles that is designed to stop things sliding off a table at sea when the boat is heeled. *Foil-name for the T- or L-shaped hydroplaning appendage that lifts a hull out of the water while sailing. The vertical component is similar to a conventional dagger board but much narrower due to the high sailing speed of foiling craft. 120 mm is typical in a foiling Moth of 3.3 m length. The vertical component is a symmetrical NASA foil shape. The main vertical foil is often angled forward to prevent air being sucked down the leading edge and creating a disturbed water flow. The winglets or blades are asymmetrical NASA foil shapes like a plane wing. In most foiling boats the whole wing can moved up or down – either automatically and/or partly controlled by a crew member to adjust the amount of lift needed. This depends mainly on wind and boat speeds. Winglets with a wider cross section give more lift at lower speeds but have more drag as speed increases whereas narrower ones have less lift but less drag at higher speed. Foils are usually made of lightweight carbon fibre because of its extreme strength and stiffness. *Frame - the transverse structure that gives a boat its cross-sectional shape. Frames may be solid or peripheral. They may be made of wood, plywood, steel, aluminium or composite materials. They may be removed after construction to save weight or to be reused or left in-situ. In ancient shipbuilding the frames were put in after the planking but now most boats are built with the frames first. This gives greater control over the shape. "Lofting" is the process used to create life-size drawings of frames so they can be manufactured. Today frames can be cut directly from a computer programme by a robot, with extreme accuracy. In old heavily built, square rigged ships, the frames were made up of 4 individual timbers called futtocks, as it was impossible to make the shape from a single piece of wood. The futtock closest to the keel was the ground futtock and the other pieces were called upper futtocks. *Freeboard- the distance between the water line and the deck when loaded. Boats using sheltered waters can have low free board but seagoing vessels need high freeboard. *Furling headsail -a jib or other headsail that automatically rolls around a semi rigid forestay when a line is pulled. The lower section of the furling gear has a spring-loaded retrieval system that rolls up the headsail. These are often used in cruising boats or when a yacht is sailed short-handed. The operating lines are operated from the safety of the cockpit avoiding crew working on the exposed foredeck. On very large yachts the furling gear is attached to an electric motor for ease of use. *Garboard - The strake immediately adjacent to the keel in a traditional wooden boat. *Gimbaled stove/compass-a pivoting apparatus that allows a stove or compass to swing in two planes at the same time so that it remains more or less level. This makes the compass needle steady and easier to read and allows food to be cooked (carefully) in seaway. *Gooseneck - a universal joint, usually made of stainless steel, that joins the boom to the mast. Many goose necks can be raised or lowered on a short section of track fixed to the mast. *Grab rail- a length of strong wood, often mahogany, or stainless steel tube, with short legs, through bolted to a cabin top, so that crew making their way forward on a sloping and wet side deck have a firm handhold. *Gudgeon- a stainless steel fitting, attached to a rudder head, in pairs, with parallel holes in which the rudder pintle pivots . *Gunwale - The upper, outside longitudinal structural member of the hull. *Hatch - A lifting or sliding opening into the cabin or deck for the loading of cargo or people. *Heads - marine toilet. An abbreviation of the term catsheads which was the normal place of toileting in square rigger days. Always used in the plural. *Horn Cleat - see cleat *Hull - The main body of a ship or other vessel, including the bottom, sides, and deck. *Hydrofoil-An inverted T or an L-shaped keel/dagger board device, with hydro dynamic lifting ability, that extends vertically downwards under the hull. As boat speed increases the hull lifts completely out of the water so drag is reduced and hull speed dramatically increased. The AC 72 ft catamaran New Zealand reached 40 knots in 17 knots of wind with almost no heeling, using hydrofoils in September 2012.〔TV1 news, NZ, 6 Sept 2012〕 Sometimes called foiling or foil sailing. Most commonly used in 11 feet Moth sail boats. Also used in powerboats. *Innerliner - The cockpit or deck mold of the inside or top of a GRP boat, fitted inside and joined to the (outside) hull. *Inwale - The upper, inner longitudinal structural member of the hull, to which topside panels are fixed. In USA this is usually called the sheer clamp. *Jib stick- A short, light spar used to hold out the jib when sailing almost directly down wind or in light airs when the jib may otherwise collapse or flap. The out board end may have a U shape to take the jib sheet or a point to go into the clew. The inboard end may be held or fastened to some convenient point such as a side stay or a purpose made fitting. *Keel - The main central member along the length of the bottom of the boat. It is an important part of the boat's structure which also has a strong influence on its turning performance and, in sailing boats, resists the sideways pressure of the wind *Keelson - An internal beam fixed to the top of the keel to strengthen the joint of the upper members of the boat to the keel. *King plank - A flat, notched (nibbed) timber laid over the foredeck beams between the front of a cockpit or cabin and the stem. The notches or nibbs are designed so that the tapering deck planks do not end in a point which could be a weak point. *Knee - A short L shaped piece of wood that joins or strengthens boat parts that meet at about 60 to 120 degrees. It may be a natural crook (e.g. apple, oak, pohutukawa) or sawn from a larger length of timber or laminated in a wooden vessel. Commonly seen on thwarts to join topsides or keelsons to join transoms. A hanging knee fits upside down e.g. underneath a thwart rather than on top. Hanging knees often support carlins where a full frame would be inconvenient. *Locker - an enclosed space to store sails, anchors, personal effects, tools and supplies *Mast - A vertical pole on a ship which supports sails or rigging. If a wooden, multi-part mast, this term applies specifically to the lowest portion. *Mast step - A socket, often strengthened, to take the downward thrust of the mast and hold it in position. May be on the keel or on the deck in smaller craft. *Moon pool - An opening in the bottom of the hull giving access to the water below, allowing access to the sea. Similar to wet porch. *Mizzen-the permanent mast and sail set aft in a sailboat with 2 or more masts. *Newel Post- turned wooden posts, from floor to ceiling, to one side of the cabin in a yacht. Serves as a handhold when a boat is at sea. *Oar A wooden pole flattened at the outboard-end so it grips the water when pulled. Oars are normally used in pairs to propel a rowboat forward. Differs from a paddle by being longer and gaining leverage by passing through a rowlock which acts as a fulcrum to produce forward motion. Modern oars are often made from plastic or hollow carbon fibre in racing oars. A single oar can be leveraged against a U shape notch in the stern of a row boat to scull. The sculler stands and moves the oar in a sideways motion to produce forward motion in calm waters. A balanced oar is one that has weight added (either by extra wood or lead inside the handle)to the inboard end to balance the additional outboard length. In a rowing dinghy with 7–8 feet oars the balance point is about 12 inches outboard of the rowlocks. *Painter-a short rope tied to the bow of a small boat, which can be held by a person. Used to control a boat while unloading from a trailer or loading/unloading from a beach. *Parrot beak-a stainless steel fitting on the end of a spinnaker pole, consisting of a mounting with a retractable spring-loaded pin that is controlled remotely by way of a cord. When the cord is pulled it releases the spinnaker sheet so the spinnaker can be recovered by crew on deck. *Pintle a short section of stainless steel rod, about 6-12mm in diameter, mounted on a stainless steel bracket, that is bolted to the transom of a sail boat, so that the pin is inserted in the gudgeon hole. *Planing Plank - a narrow, flat bottom keel about 150mm wide on a high speed deep or medium V powered planning craft. In flat water the craft would plane on this narrow plank giving increased speed. In choppy water the ride was unsettled. Steering accuracy when cornering was difficult as the craft swung wide. A concept used in power craft in the 1970s and 1980s but replaced by deeper V hulls with angles of more than 21 degrees from the 1990s. *Prod- a very strong, light, hollow tapered pole, often made of carbon fibre, attached to the bow of a modern racing yacht, enabling it to carry a spinnaker or other down-wind sail with the luff in line with the centreline of the boat. In some yachts, such as the modern 49er, the prod is retracted through a hole in the bow when sailing upwind. Larger prods, such as on an AC72, are secured by dolphin strikers to prevent the prod bending upwards or breaking. *Ratlines (sometimes ''ratlins'') - Groups of side stays on a square rigged ship that have horizontal lines placed for feet, enabling crew to rapidly ascend to the yards. *Rib - A thin strip of pliable timber laid athwart-wise inside the hull, from inwale to inwale, at regular close intervals to strengthen the exterior planking. The rib is often steamed to increase flexibility. The rib is traditionally fixed to the planking by rivets or copper nails bent over on the inside. This method is still used in small clinker built dinghies and similar craft. Ribs are attached after the planking is constructed. Ribs differ from frames or futtocks in being far smaller dimensions and bent in place compared to frames or futtocks which are normally sawn to shape, or natural crooks that are shaped to fit with an adze, axe or chisel. *Rigging- wire or rod used to hold up a mast. Since the 1960s stainless steel wire has become universal in the developed world. Elsewhere galvanized wire or even rope may be used because of its availability and cheapness.3 types of stainless steel wire are commonly used. Type 1 x 19 is a non-flexible wire used for standing rigging such as stays. Type 7 x 7 is a semi flexible wire used for luff wires in sails, halyards (sometimes plastic coated) trapeze wires and light halyards. Type 7 x 19 is used for all halyards, wire sheets, vangs and strops that must run through a pulley (sheave). The common way of attaching wire is to form a small loop at the end which is fixed in place by clamping a soft metal swage over the free ends. Talurite is a common brand of swagging. The wire loop is then fastened to a rigging screw with a bow shackle to the chain plate. Kevlar rope is sometimes used in place of wire in small sailboats. *Rowlock - Pronounced Rolick. A 'U' shaped metal device that secures an oar and acts as a fulcrum during the motion of rowing. Sometimes called an oarlock in the USA. The Rowlock is attached with a swivelling pin to the gunwale in a row boat. Commonly made from galvanized steel, bronze or plastic. Before the availability of metal the oar was normally levered against 2 wooden pins called Thole pins inserted in the gunwale. Tholepins are still used in some third world nations. In a narrow row boat the rowlocks are held well outboard in a lightweight outrigger (rigger) which is often equipped with a locking pin to hold the oar securely. *Rudder - A steering device usually at the rear of the hull created by a turn-able blade on a vertical axis *Sampson post - A strong vertical post used to support a ship's windlass and the heel of a ship's bowsprit. *Scuppers - Gaps in the bulwarks which enables sea or rain water to flow off the deck. *Shackle - a small, U shape, stainless steel or galvanized steel secured with a screw type pin at the open end of the U. Some types have spring-loaded pins that snap shut. *Sheave box - a plastic or stainless steel box that holds a pulley that is fixed in position such as on a mast head so that the angle of the rope (halyard)is restricted. *Sheer - The generally curved shape of the top of the hull when viewed in profile. The sheer is traditionally lowest amidships to maximize freeboard at the ends of the hull. Sheer can be reverse, higher in the middle to maximize space inside, or straight or a combination of shapes. *Sensor - A small electronic component which can be embedded in a hull skin, keel, rudder, mast, oar or sail of a very-high-performance craft to measure the laminar flow of air or water. Pioneered in New Zealand using technology from Formula 1 racing. Now used in rowing skiffs or racing oars to determine forces such as bending load and optimum angle of attack of the blade. Larger craft such as America Cup boats have readout displays on board so minute changes in sail angle can be related to speed and then duplicated at a later date. *Sheet - A rope used to control the position of a sail e.g. the main sheet controls the position of the main sail. *Skeg - A long tapering piece of timber fixed to the underside of a keel near the stern in a small boat to aid directional stability, especially in a kayak or rowboat. *Spar - A length of timber, aluminium, steel or carbon fibre of approximately round or pear shape that is used to support sails. Such as a mast, boom, gaff, yard, bowsprit, prod, boomkin, pole or dolphin striker . *Sole-the floor of a cabin or cockpit. Often the cabin floor is made in sections that can be lifted quickly to gain access to the bilges in the event of a leak. Cockpit floors on yachts are often self-draining so that water will drain out even when the vessel is sailing at an extreme angle. In many high speed skiffs the craft is fitted with a sole angled aft to rapidly drain the spray through an open transom. Often this type of sole is called a false floor. *Spinnaker- sometimes called a kite in Australia or New Zealand. A large, lightweight, down-wind sail used on fore and aft rigged yachts such as sloops to dramatically increase sail area. The sail is hoisted by a halyard attached by a ring to the head of the sail. The windward, luff, corner is secured by a sheet often called a preventer. The preventer runs through a parrot beak attached to the end of a spinnaker pole. Until recently the pole was usually secured by a parrot beak to a ring on the lower mast. The leeward, clew, corner is controlled by a sheet. In double luff (parallel sided) spinnakers, the 2 sheets are interchangeable. In some very modern racing yachts the pole is replaced by a prod which is fixed in place at the bow. Some spinnakers are single luff, which are flatter and with a longer luff enabling them to be carried more easily on a reach. In small planning sailboats such as 18 ft skiffs, huge spinnakers cause dramatic increases in speed and spectacular, on the edge, sailing. *Spreaders- two angled, metal struts, attached about mid height on a mast, for the purpose of keeping the side stays taunt. Spreaders are usually swept rearwards approximately in line of the side stay between the hounds and the chain plate. They help hold the mast straight (in column) when under heavy load such as when carrying a spinnaker on a tight reach. *Spring - The amount of curvature in the keel from bow to stern when viewed side on. The modern trend is to have less spring in order to have less disturbance to water flow at higher speeds to aid planing. *Stanchions - A series of narrow but strong posts, often made of marine grade stainless steel, designed to hold life lines around the outer edge of a deck. Stanchions are often attached to both the deck and a toe rail or bulwark for added strength. *Stainless steel- mild steel to which small percentages of copper, chromium and sometimes nickel are added to make a very strong steel that is does not rust much. Marine grade stainless steel 316 containing more nickel, is even more rust resistant. Can be made into rod, tubes, sheet or pressed into a wide variety of shapes for marine fittings. *Stays/shrouds - Standing or running rigging which hold a spar in position e.g. sidestay, forestay, backstay. Formerly made of rope, these days usually stainless steel wire. *Stem - A continuation of the keel upwards at the front of the hull *Stern - The back of the boat *Stern sheets a flat area or deck, inboard of the transom in a small boat. It may contain hatches to access below decks or provide storage on deck for life saving equipment. *Strake - A strip of material running longitudinally along the vessel's side, bilge or bottom. Sometimes called a stringer. *Stringer-Batten in USA. A long relatively thin, knot free length of wood, running fore and aft, often used to reinforce planking on the inside of the hull, especially when thin planking is used. See strake *Synthetic rope - There are 4 common ropes in use. Polyester, also called Dacron or Terylene, is a strong, low stretch rope, usually plaited (braided) used for running rigging. Nylon is a strong, but elastic rope, used for mooring lines and anchor warps as it resists shock loads. It is usually laid (twisted) so that it is easier to grip when hauling. Polypropylene is a light, cheap, slippery rope, that floats. It is much weaker than the previous ropes. It weakens when exposed to sunlight. It is usually laid construction. Commonly used on commercial fishing boats using nets. Kevlar is an extremely strong fibre that is now made into ropes with almost no stretch. Expensive. Suited to halyards instead of stainless steel wire. Often used on racing yachts to replace polyester when powerful winches are used. Kevlar ropes can be much smaller in diameter than polyester for the same strength. This saves windage on a racing yacht. Usually braided. *Taff rail-a railing, often ornate, at the extreme stern of a traditional square rigged ship. In light air conditions an extra sail was set on a temporary mast from the taff rail. *Thwart - A seat, usually transverse, that is used to maintain the shape of the topsides in a small boat. *Tiller- A handle made of wood, steel or carbon fibre that is attached to the top of a rudder, often via a post, which enables the helmsman to steer the boat. *Tiller extension-A long, lightweight handle attached to the forward end of the tiller which enables the helmsman to steer from a position from the side deck or outboard of a side deck on a high performance yacht. For example, from a trapeze. *Toe rail - A upright longitudinal strip of timber fastened to the fore deck near the sheer. It is placed so that crew working on the foredeck can brace their toe or foot against it especially when the boat is heeled. *Topping Lift-a rope running from the aft end of the boom, through a block at the masthead and down to a cleat at the foot of the mast. Used for holding the boom up when the mainsail is not being used. *Topsides - The side planking of a boat from the waterline to the sheer. *Transom - A wide, flat or slightly curved, sometimes vertical board at the rear of the hull, which, on small power boats, is often designed to carry an outboard motor. Transoms increase width and also buoyancy at the stern. On outboard boats the stern is often the widest point to provide displacement to carry a large outboard and to resist the initial downward thrust of a planning craft. Sometimes the term tuck is used in a sail boat. *Trapeze- a wire and belt device allowing a crew member to lie near horizontal with their feet braced against the gunwhale in order to counter act the healing force of the wind acting on the sails of a centre board racing yacht. A thin stainless steel wire is attached to the mast at about 3/4 height and to a belt worn by the crew member via a hook. When tacking the sailor must swing in, unhook, move to the other side of the yacht and reattach the hook on the opposite tack. Agility is required. The crew holds the tail of the jib sheet for trimming and balance. In a few classes the helmsman and/or helmsman and all crew, use trapezes. *Wand-a devise fitted to a foiling yacht to give control over the ride height and "z" factor(foil rise and fall). Consists of a carbon tube that pivots from the bow attached to an internal wire or rod that is attached to arod in the centre (main) foil). The rod runs to the main foil blades (wings)to control their angle. The wand can be set fixed but since about 2009 a dial is fitted that allow the skipper to adjust the foil blade angles/wand height. Some craft are fitted with dual wands for more precise control. *Washboard - a panel that slides vertically in small boat's companionway acting as a removable door *Warp-anchor rope. Traditionally made of natural fibre such as hemp, modern warps are made of stronger, lighter, synthetic fibre, often laid nylon, which is elastic so absorbing shock loads which would otherwise pull out the anchor. Warps are normally at least 3 times the depth of the water. In strong wind and/or current the warp should be at least 6 times the water depth. *Water tank - a large irregular shaped container(s), often made of stainless steel, that is usually fitted into the bilges of a voyaging boat. The tank often has a deck mounted inlet, a vent pipe and a pump to move water to taps, showers etc. Mounted low in the hull, it adds significantly to stability when full. *Winch-a geared mechanical device used on yachts for trimming (adjusting)sail sheets, for hoisting large sails with halyards, for hauling in an anchor or on a boat trailer for hauling a boat out of the water. The normal turret winch is set on the aft side deck for trimming headsails and or a spinnaker. Manual trimming winches are operated by grinding the handle in a circle initially, then pulling back and forwards on a short lever while a second person tails (pulls to keep tension on the sheet)to obtain optimum force. Some winches are self-tailing or the sheet can be cleated to prevent slippage. On larger yachts winches can be operated by electric motors. Typically on America's cup yachts large pedestal winches are used which can be operated by two people at the same time. Because of the force needed, especially in tacking duels, winch grinders are usually very large and strong men. *Wind pennant-a small wind indicator balanced on a pivot, usually fitted to the mast head, to indicate wind direction. Can be made of plastic, stainless steel or sail cloth. *Wheelhouse - a permanent, raised shelter, with large windows, often located midships or aft, from which the helmsman steers. Usually contains all the boats controls, instruments and electronics. It gives the helmsman good visibility 360 degrees and keeps them out of bad weather and spray. The wheelhouse may be open aft or have access to the side decks so when operating short-handed the helmsman can attend lines. *Yard - A horizontal spar on a square rigged ship fitted to the forward side of a mast, holding a square sail forward of the shrouds. Each square sail hangs from its own yard. Sails are furled by seamen who bend over the yard and use both hands to haul up the sail. The sail is trimmed to the wind by braces leading from the yard arms (ends of the yard) aft (or forward) to another mast, or down to the deck. Compare to "gaff" and "boom", which attach to the aft side of the mast and hold a "fore-and-aft" sail aft of the shrouds. A square sail trims to either side of athwartships, and a fore-and-aft sail trims to either side of fore-and-aft. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Boat building」の詳細全文を読む スポンサード リンク
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