1.
Watercraft
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Watercraft are water-borne vehicles including ships, boats, hovercraft and submarines. Watercraft usually have propulsive capability and hence are distinct from a device that merely floats. Most watercraft would be described as either a ship or a boat, however, there are numerous craft which many people would consider neither a ship nor a boat, such as, surfboards, underwater robots, seaplanes, jetskis and torpedoes. Although ships are larger than boats, the distinction between those two categories is not one of size per se. Ships are typically large ocean-going vessels, whereas boats are smaller, and typically travel most often on inland or coastal waters. A rule of thumb says a boat can fit on a ship, but a ship cant fit on a boat, local law and regulation may define the exact size that distinguishes a ship from a boat. A merchant ship is any floating craft that transports cargo for the purpose of earning revenue, in that context, the term watercraft is rarely used to describe any individual object, rather the term serves to unify the category that ranges from jet skis to aircraft carriers. Such a vessel may be used in saltwater and freshwater, for pleasure, recreation, physical exercise, commerce, in general, the purpose of a water vehicle identifies its utility with a maritime industry sub-sector. The design from which a vehicle is created usually seeks to achieve a balance between internal capacity, speed and seaworthiness. Propulsion is the application of technology in watercraft. Current technological development seeks to identify cheaper, renewable and less polluting sources of propulsion for watercraft of all shapes and sizes, secondary applications of technology in watercraft have been those of used structural materials, navigation aids, and in the case of warships, weapon systems. Watercraft registration is the registration of a watercraft with a government authority, identification consists of an alphanumeric string called a vessel registration number that is issued in the United States by the states Department of Motor Vehicles. Navigation aids have varied over time, from observation, to mechanical mechanisms. Since the early 20th century, there has been a development in technologies which allow force projection from a naval task force to a land objective using marine infantry. The Canadian Museum of Civilization - Native Watercraft in Canada A History of Recreational Small Watercraft Recreational Watercraft
2.
Ship
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Historically, a ship was a sailing vessel with at least three square-rigged masts and a full bowsprit. Ships are generally distinguished from boats, based on size, shape, Ships have been important contributors to human migration and commerce. They have supported the spread of colonization and the trade, but have also served scientific, cultural. After the 16th century, new crops that had come from, Ship transport is responsible for the largest portion of world commerce. As of 2016, there were more than 49,000 merchant ships, of these 28% were oil tankers, 43% were bulk carriers, and 13% were container ships. Military forces operate vessels for naval warfare and to transport and support forces ashore, the top 50 navies had a median fleet of 88 surface vessels each, according to various sources. There is no definition of what distinguishes a ship from a boat. Ships can usually be distinguished from boats based on size and the ability to operate independently for extended periods. A legal definition of ship from Indian case law is a vessel that carries goods by sea, a common notion is that a ship can carry a boat, but not vice versa. American and British 19th Century maritime law distinguished vessels from other craft, ships and boats fall in one legal category, a number of large vessels are usually referred to as boats. Other types of vessel which are traditionally called boats are Great Lakes freighters, riverboats. Though large enough to carry their own boats and heavy cargoes, in most maritime traditions ships have individual names, and modern ships may belong to a ship class often named after its first ship. The first known vessels date back about 10,000 years ago, the first navigators began to use animal skins or woven fabrics as sails. Affixed to the top of a pole set upright in a boat and this allowed men to explore widely, allowing for the settlement of Oceania for example. By around 3000 BC, Ancient Egyptians knew how to assemble wooden planks into a hull and they used woven straps to lash the planks together, and reeds or grass stuffed between the planks helped to seal the seams. Sneferus ancient cedar wood ship Praise of the Two Lands is the first reference recorded to a ship being referred to by name, the ancient Egyptians were perfectly at ease building sailboats. A remarkable example of their skills was the Khufu ship. Aksum was known by the Greeks for having seaports for ships from Greece, a panel found at Mohenjodaro depicted a sailing craft
3.
Boat
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A boat is a watercraft of a large range of sizes designed to float, plane, work or travel on water. Small boats are found on inland waterways or in protected coastal areas. However, boats such as the whaleboat were designed for operation from a ship in an offshore environment, in naval terms, a boat is a vessel small enough to be carried aboard another vessel. Another less restrictive definition is a vessel that can be lifted out of the water, some definitions do not make a distinction in size, as bulk freighters 1,000 feet long on the Great Lakes are called oreboats. For reasons of tradition, submarines are usually referred to as boats rather than ships, regardless of their size. Ships are generally distinguished from boats based on their size, shape. Boats have a variety of shapes, sizes and construction methods due to their intended purpose. Canoe-type boats have used since prehistoric times and various versions are used throughout the world for transportation. Fishing boats vary widely in style partly to local conditions. Pleasure boats include ski boats, pontoon boats, and sailboats, house boats may be used for vacationing or long-term housing. Small boats can provide transport or convey cargo to and from large ships, lifeboats have rescue and safety functions. Boats can be powered by power, wind power and motor power. Dugouts are the oldest type of boats found by archaeologists, the earliest boats are thought to have been logboats, and the oldest boats found by archaeological excavation date from around 7, 000–10,000 years ago. The oldest recovered boat in the world is the Pesse canoe and this canoe is exhibited in the Drents Museum in Assen, Netherlands. Other very old dugout boats have also been recovered, rafts have operated for at least 8,000 years. A7, 000-year-old seagoing reed boat has been found in Kuwait, boats were used between 4000 and 3000 BC in Sumer, ancient Egypt and in the Indian Ocean. Boats played an important role in the commerce between the Indus Valley Civilization and Mesopotamia, evidence of varying models of boats has also been discovered at various Indus Valley archaeological sites. Uru craft originate in Beypore, a village in south Calicut, Kerala and this type of mammoth wooden ship was constructed using teak, without any iron, and had a transport capacity of 400 tonnes
4.
Sea state
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In oceanography, a sea state is the general condition of the free surface on a large body of water—with respect to wind waves and swell—at a certain location and moment. A sea state is characterized by statistics, including the height, period. The sea state varies with time, as the conditions or swell conditions change. The sea state can either be assessed by an observer, like a trained mariner, or through instruments like weather buoys. In case of measurements, the statistics are determined for a time interval in which the sea state can be considered to be constant. This duration has to be longer than the individual wave period. Typically, records of one hundred to one thousand wave-periods are used to determine the wave statistics, the WMO sea state code largely adopts the wind sea definition of the Douglas Sea Scale. The direction from which the swell is coming should be recorded, in engineering applications, sea states are often characterized by the following two parameters, The significant wave height H1/3 — the mean wave height of the one third highest waves. The sea state is in addition to these two parameters also described by the wave spectrum S which is a function of a wave height spectrum S, some wave height spectra are listed below. The dimension of the spectrum is =, and many interesting properties about the sea state can be found from the spectrum. In addition to the term wave statistics presented above, long term sea state statistics are often given as a joint frequency table of the significant wave height. From the long and short term statistical distributions it is possible to find the extreme values expected in the life of a ship. Surviving the once in 100 years or once in 1000 years sea state is a demand for design of ships. Beaufort scale Cross sea Douglas Sea Scale Bowditch, Nathaniel, American Practical Navigator,9, United States Hydrographic Office, OCLC31033357 Faltinsen, O. M. Sea Loads on Ships and Offshore Structures, ISBN 0-521-45870-6
5.
Ship motions
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Ship motions are defined by the six degrees of freedom that a ship, boat or any other craft can experience. Heave is the vertical motion, excessive downward heave can swamp a ship. Sway is the lateral motion. This motion is generated either by the water and wind currents exerting forces against the hull or by the ships own propulsion. This movement can be compared to the drift from its course. Surge is the longitudinal motion imparted by maritime conditions. The vertical/Z axis, or yaw axis, is a line running vertically through the ship. A yaw motion is a side-to side movement of the bow, the lateral/Y axis, transverse axis, or pitch axis is an imaginary line running horizontally across the ship and through the centre of gravity. A pitch motion is a movement of the bow and stern of the ship. The longitudinal/X axis, or roll axis, is a line running horizontally through the length of the ship, through its centre of gravity. A roll motion is a side-to-side or port-starboard tilting motion of the superstructure around this axis, there are three special axes in any ship, called vertical, lateral and longitudinal axes. The movements around them are known as roll, pitch and yaw, pitch is the up/down rotation of a vessel about its lateral/Y axis. An offset or deviation from normal on this axis is referred to as trim or out of trim, roll is the tilting rotation of a vessel about its longitudinal/X axis. An offset or deviation from normal on this axis is referred to as list or heel, heel refers to an offset that is intentional or expected, as caused by wind pressure on sails, turning, or other crew actions. List normally refers to an unintentional or unexpected offset, as caused by flooding, battle damage, shifting cargo, the rolling motion towards a steady state angle due to the ships own weight distribution is referred in marine engineering as heel. Yaw is the rotation of a vessel about its vertical/Z axis. An offset or deviation from normal on this axis is referred to as deviation or set, there are methods for both passive and active motion stabilization used in some designs. They include static hull features such as skegs and bilge keels, or active devices like counterweights, antiroll tanks
6.
Drillship
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A drillship is a merchant vessel designed for use in exploratory offshore drilling of new oil and gas wells or for scientific drilling purposes. In most recent years the vessels are used in deepwater and ultra-deepwater applications, the first drillship was the CUSS I, designed by Robert F. Bauer of Global Marine in 1955. The CUSS I had drilled in 400 feet deep waters by 1957, Robert F. Bauer became the first president of the Global Marine in 1958. In 1961 Global Marine started a new drillship era and they ordered several self-propelled drillships each with a rated centerline drilling of 20,000 foot-wells in water depths of 600 feet. The first was named CUSS II, a 5, 500-deadweight-ton vessel, built by a Gulf Coast shipyard, the vessel was almost twice the size of the CUSS I, and became the world’s first drillship built as new construction which set sail in 1962. In 1962 The Offshore Company elected to build a new type of drillship and this new drillships would feature a first ever anchor mooring array based on a unique turret system. The vessel was named Discoverer I, the Discoverer I had no main propulsion engines, meaning they needed to be towed out to the drill site. The drillship can be used as a platform to carry out maintenance or completion work such as casing and tubing installation, subsea tree installations. Drillships are often built to the specification to meet the requirements set by the oil production company and/or investors. From the first drillship CUSS I to the Deepwater Asgard the fleet size has been growing ever since, in 2013 the worldwide fleet of drillships tops 80 ships, more than double its size in 2009. Drillships are not only growing in size but also in capability with new technology assisting operations from academic research to ice-breaker class drilling vessels. U. S. President Barack Obamas decision in late March 2010 to expand U. S. domestic exploratory drilling seems likely to further developments of drillship technology. Drillships are just one way to various types of drilling. This function can also be performed by semi-submersibles, jackups, barges, drillships have the functional ability of semi-submersible drilling rigs and also have a few unique features that separate them from all others. A drillship has greater mobility and can move quickly under its own propulsion from drill site to site in contrast to semi-submersibles and jackup barges. Drillships have the ability to save time sailing between oilfields worldwide, a drillship takes 20 days to move from the Gulf of Mexico to the Offshore Angola. Whereas, a drilling unit must be towed and takes 70 days. Drillship construction cost is higher than that of a semi-submersible
7.
Ferry
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A ferry is a merchant vessel used to carry passengers, and sometimes vehicles and cargo as well, across a body of water. Most ferries operate regular return services, a passenger ferry with many stops, such as in Venice, Italy, is sometimes called a water bus or water taxi. Ferries form a part of the transport systems of many waterside cities and islands. However, ship connections of much larger distances may also be called ferry services, the profession of the ferryman is embodied in Greek mythology in Charon, the boatman who transported souls across the River Styx to the Underworld. Speculation that a pair of oxen propelled a ship having a wheel can be found in 4th century Roman literature Anonymus De Rebus Bellicis. Though impractical, there is no reason why it could not work and such a ferry, see When Horses Walked on Water, Horse-Powered Ferries in Nineteenth-Century America. The Marine Services Company of Tanzania offers passenger and cargo services in three of the African Great Lakes viz, Lake Victoria, Lake Tanganyika and Lake Nyasa. It also operates one of the oldest ferries in the region, Ferries from Great Britain also sail to Belgium, Denmark, the Netherlands, Norway, Spain and Ireland. Some ferries carry mainly tourist traffic, but most also carry freight, in Britain, car-carrying ferries are sometimes referred to as RORO for the ease by which vehicles can board and leave. The busiest single ferry route is across the part of Øresund. Before the Øresund bridge was opened in July 2000, car and car & train ferries departed up to seven times every hour, in 2013, this has been reduced, but a car ferry still departs from each harbor every 15 minutes during daytime. The route is around 2.2 nautical miles and the crossing takes 22 minutes, today, all ferries on this route are constructed so that they do not need to turn around in the harbors. This also means that the ferries lack natural stems and sterns, due to the same circumstances, starboard and port-side are dynamic and depending of in what direction the ferry sails. Despite the short crossing, the ferries are equipped with restaurants, cafeteria, kiosks, large cruiseferries sail in the Baltic Sea between Finland, Åland, Sweden, Estonia, Latvia and Saint Petersburg, Russia and from Italy to Sardinia, Corsica, Spain and Greece. In many ways, these ferries are like cruise ships, also many smaller ferries operate on domestic routes in Finland, Sweden and Estonia. The south-west and southern parts of the Baltic Sea has several routes mainly for heavy traffic, on the longer of these routes, simple cabins are available. In Istanbul, ferries connect the European and Asian shores of Bosphorus, as well as Princes Islands, in 2014 İDO transported 47 million passengers, the largest ferry system in the world. Due to the numbers of freshwater lakes and length of shoreline in Canada
