Aboat is awatercraft of a large range of types and sizes, but generally smaller than aship, which is distinguished by its larger size or capacity, its shape, or its ability to carry boats.
Small boats are typically used on inland waterways such asrivers andlakes, or in protected coastal areas. However, some boats (such aswhaleboats) were intended for offshore use. In modernnaval terms, a boat is a vessel small enough to be carried aboard a ship.[1]
Boats vary in proportion and construction methods with their intended purpose, available materials, or local traditions.Canoes have been used since prehistoric times and remain in use throughout the world for transportation, fishing, and sport.Fishing boats vary widely in style partly to match local conditions.Pleasure craft used inrecreational boating include ski boats,pontoon boats, andsailboats.House boats may be used for vacationing or long-term residence.Lighters are used to move cargo to and from large ships unable to get close to shore.Lifeboats have rescue and safety functions.
The earliest watercraft are considered to have beenrafts. These would have been used for voyages such as the settlement of Australia sometime between 50,000 and 60,000 years ago.
A boat differs from araft by obtaining its buoyancy by having most of its structure exclude water with a waterproof layer, e.g. the planks of a wooden hull, the hide covering (or tarred canvas) of acurrach. In contrast, a raft is buoyant because it joins components that are themselves buoyant, for example, logs, bamboo poles, bundles of reeds, floats (such as inflated hides, sealed pottery containers or, in a modern context, empty oil drums). The key difference between a raft and a boat is that the former is a "flow through" structure, with waves able to pass up through it. Consequently, except for short river crossings, a raft is not a practical means of transport in colder regions of the world as the users would be at risk ofhypothermia. Today that climatic limitation restricts rafts to between 40° north and 40° south, with, in the past, similar boundaries that have moved as the world's climate has varied.[2]: 11
Types
The earliest boats may have been eitherdugouts or hide boats.[2]: 11 The oldest recovered boat in the world, thePesse canoe, found in theNetherlands, is a dugout made from the hollowed tree trunk of aPinus sylvestris that was constructed somewhere between 8200 and 7600 BC. Thiscanoe is exhibited in theDrents Museum in Assen, Netherlands.[3][4] Other very old dugout boats have also been recovered.[5][6][7] Hide boats, made from covering a framework with animal skins, could be equally as old as logboats, but such a structure is much less likely to survive in an archaeological context.[8]: 63
Plank-built boats are considered, in most cases, to have developed from the logboat. There are examples of logboats that have been expanded: by deforming the hull under the influence of heat, by raising up the sides with added planks, or by splitting down the middle and adding a central plank to make it wider. (Some of these methods have been in quite recent use – there is no simple developmental sequence). The earliest known plank-built boats are from the Nile, dating to the third millennium BC. Outside Egypt, the next earliest are from England. TheFerriby boats are dated to the early part of the second millennium BC and the end of the third millennium.[8]: 63, 66–67 Plank-built boats require a level of woodworking technology that was first available in theNeolithic with more complex versions only becoming achievable in theBronze Age.[9]: 59
Towed – either by humans or animals from a river or canal bank (or in very shallow water, by walking on the sea or river bed) or by another vessel.
Powered bymachinery, such as internal combustion engines, steam engines or by batteries and an electric motor. Any one vessel may use more than one of these methods at different times or in combination.[9]: 33
A number of large vessels are usually referred to as boats.Submarines are a prime example.[10] Other types of large vessels which are traditionally called boats includeGreat Lakes freighters,riverboats, andferryboats.[11] Though large enough to carry their own boats and heavy cargo, these vessels are designed for operation on inland or protected coastal waters.
Thehull is the main, and in some cases only, structural component of a boat. It provides both capacity andbuoyancy. Thekeel is a boat's "backbone", a lengthwise structural member to which the perpendicular frames are fixed. On some boats, adeck covers the hull, in part or whole. While aship often has several decks, a boat is unlikely to have more than one. Above the deck are oftenlifelines connected tostanchions,bulwarks perhaps topped bygunnels, or some combination of the two. Acabin may protrude above the deck forward, aft, along the centerline, or cover much of the length of the boat. Vertical structures dividing the internal spaces are known asbulkheads.
The forward end of a boat is called thebow, the aft end thestern. Facing forward the right side is referred to asstarboard and the left side asport.
Until the mid-19th century, most boats were made of natural materials, primarily wood, although bark and animal skins were also used. Early boats include thebirch barkcanoe, the animal hide-coveredkayak[12] andcoracle and thedugout canoe made from a single log.
By the mid-19th century, some boats had been built with iron or steel frames but still planked in wood. In 1855ferro-cement boat construction was patented by the French, who coined the name "ferciment". This is a system by which a steel or iron wire framework is built in the shape of a boat's hull and covered over with cement. Reinforced with bulkheads and other internal structures it is strong but heavy, easily repaired, and, if sealed properly, will not leak or corrode.[13][14]
As the forests of Britain and Europe continued to be over-harvested to supply the keels of larger wooden boats, and theBessemer process (patented in 1855) cheapened the cost of steel, steel ships and boats began to be more common. By the 1930s boats built entirely of steel from frames to plating were seen replacing wooden boats in many industrial uses and fishing fleets. Private recreational boats of steel remain uncommon. In 1895 WH Mullins produced steel boats of galvanized iron and by 1930 became the world's largest producer of pleasure boats.
Mullins also offered boats in aluminum from 1895 through 1899 and once again in the 1920s,[15] but it was not until the mid-20th century thataluminium gained widespread popularity. Though much more expensive than steel, aluminum alloys exist that do not corrode in salt water, allowing a similar load carrying capacity to steel at much less weight.
Around the mid-1960s, boats made offiberglass (aka "glass fiber") became popular, especially for recreational boats. Fiberglass is also known as "GRP" (glass-reinforced plastic) in the UK, and "FRP" (for fiber-reinforced plastic) in the US. Fiberglass boats are strong and do not rust, corrode, or rot. Instead, they are susceptible to structural degradation from sunlight and extremes in temperature over their lifespan. Fiberglass structures can be made stiffer with sandwich panels, where the fiberglass encloses a lightweight core such as balsa[16] or foam.
Cold molding is a modern construction method, using wood as the structural component. In one cold molding process, very thin strips of wood are layered over a form. Each layer is coated with resin, followed by another directionally alternating layer laid on top. Subsequent layers may be stapled or otherwise mechanically fastened to the previous, or weighted or vacuum bagged to provide compression and stabilization until the resin sets. An alternative process uses thin sheets of plywood shaped over a disposable male mold, and coated with epoxy.
A boatdisplaces its weight in water, regardless whether it is made of wood, steel, fiberglass, or even concrete. If weight is added to the boat, the volume of the hull drawn below the waterline will increase to keep the balance above and below the surface equal. Boats have a natural or designed level of buoyancy. Exceeding it will cause the boat first to ride lower in the water, second to take on water more readily than when properly loaded, and ultimately, if overloaded by any combination of structure, cargo, and water, sink.
As commercial vessels must be correctly loaded to be safe, and as the sea becomes less buoyant in brackish areas such as theBaltic, thePlimsoll line was introduced to prevent overloading.
European Union classification
Since 1998 all new leisure boats and barges built in Europe between 2.5m and 24m must comply with theEU'sRecreational Craft Directive (RCD). The Directive establishes four categories that permit the allowablewind and wave conditions for vessels in each class:[17]
Class A - the boat may safely navigate any waters.
Class B - the boat is limited to offshore navigation. (Winds up to Force 8 & waves up to 4 metres)
Class C - the boat is limited to inshore (coastal) navigation. (Winds up to Force 6 & waves up to 2 metres)
Class D - the boat is limited to rivers, canals and small lakes. (Winds up to Force 4 & waves up to 0.5 metres)
Europe is the main producer of recreational boats (the second production in the world is located in Poland). European brands are known all over the world - in fact, these are the brands that created RCD and set the standard for shipyards around the world.[18]
^abAdams, Jonathan (2013).A maritime archaeology of ships: innovation and social change in late medieval and early modern Europe. Oxford: Oxbow Books.ISBN978-1-78297-045-3.
^abMcGrail, Sean (2014).Early ships and seafaring : European water transport. South Yorkshire, England: Pen and Sword Archaeology.ISBN9781781593929.
^Williams, Charles Frederic (1895), "Vessel", in Merrill, John Houston; Williams, Charles Frederic; Michie, Thomas Johnson; Garland, David Shephard (eds.),Utmost care to Watercourses, The American and English Encyclopædia of Law, vol. 28, Edward Thompson Company, p. 440
