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78-525: Although there are several commercially available universal pH indicators, most are a variation of a formula patented by Yamada in 1933. A universal indicator is usually composed of water , 1-propanol , phenolphthalein , sodium hydroxide , methyl red , bromothymol blue , sodium bisulfite , and thymol blue . The colours that indicate the pH of a solution, after adding a universal indicator, are: The colors from yellow to red indicate an acidic solution, colours blue to violet indicate an alkaline solution and

156-601: A 1 cm sample cell. Aquatic plants , algae , and other photosynthetic organisms can live in water up to hundreds of meters deep, because sunlight can reach them. Practically no sunlight reaches the parts of the oceans below 1,000 metres (3,300 ft) of depth. The refractive index of liquid water (1.333 at 20 °C (68 °F)) is much higher than that of air (1.0), similar to those of alkanes and ethanol , but lower than those of glycerol (1.473), benzene (1.501), carbon disulfide (1.627), and common types of glass (1.4 to 1.6). The refraction index of ice (1.31)

234-522: A United Nations agency, and the Nautical Institute are seeking improved international standards for mariners. Satellite phones have improved communication and efficiency aboard sea-faring ships. This technology has contributed to crew welfare, although both equipment and fees are expensive. Ocean voyages are steeped in routine. Maritime tradition dictates that each day be divided into six four-hour periods. Three groups of watch keepers from

312-402: A cargo engineer works with the deck department during cargo operations, as well as being a watchkeeping engineer. A common engine crew for a ship includes: Many American ships also carry a motorman . Other possible positions include machinist , electrician , refrigeration engineer, and tankerman. Engine cadets are engineer trainees who are completing sea time necessary before they can obtain

390-484: A green colour indicates that a solution is neutral. Wide-range pH test papers with distinct colours for each pH from 1 to 14 are also available. Colour matching charts are supplied with the specific test strips purchased. The impact of an ethanol-based universal indicator may seem negligible at first glance. However, in the case of dilute solutions prepared with bidistilled water, this influence becomes readily discernible and measurable. [1] Water Water

468-481: A large amount of sediment transport that occurs on the surface of the earth. Deposition of transported sediment forms many types of sedimentary rocks , which make up the geologic record of Earth history . The water cycle (known scientifically as the hydrologic cycle) is the continuous exchange of water within the hydrosphere , between the atmosphere , soil water, surface water , groundwater, and plants. Water moves perpetually through each of these regions in

546-695: A mariner's off-duty time is largely a solitary affair, pursuing hobbies, reading, writing letters, and sleeping. On modern ocean-going vessels, typically registered with a flag of convenience , life has changed immensely in the last 20 years. Most large vessels include a gym and often a swimming pool for use by the crew. Since the Exxon Valdez incident , the focus of leisure time activity has shifted from having officer and crew bars, to simply having lounge-style areas where officers or crew can sit to watch movies. With many companies now providing TVs and DVD players in cabins, and enforcing strict smoking policies, it

624-754: A member of a country's martial navy . According to the 2005 CIA World Factbook , the total number of merchant ships of at least 1,000 gross register tons in the world was 30,936. In 2010, it was 38,988, an increase of 26%, across many countries . As of December 2018 , a quarter of all merchant mariners were born in the Philippines . A ship may also be categorized as to how it is operated. Ships and other watercraft are used for maritime transport. Types can be distinguished by propulsion , size or cargo type. Recreational or educational craft still use wind power, while some smaller craft use internal combustion engines to drive one or more propellers , or in

702-477: A property that is exploited by cetaceans and humans for communication and environment sensing ( sonar ). Metallic elements which are more electropositive than hydrogen, particularly the alkali metals and alkaline earth metals such as lithium , sodium , calcium , potassium and cesium displace hydrogen from water, forming hydroxides and releasing hydrogen. At high temperatures, carbon reacts with steam to form carbon monoxide and hydrogen. Hydrology

780-566: A ship, including Junior Assistant Purser , Senior Assistant Purser , Purser , Chief Purser , Medical Doctor , Professional Nurse , Marine Physician Assistant , and hospital corpsman , are considered administrative positions and are therefore regulated by Certificates of Registry issued by the United States Coast Guard . Pilots are also merchant marine officers and are licensed by the Coast Guard. Formerly, there

858-465: A strategy referred to as " slow steaming ". A ship's complement can be divided into four categories: Officer positions in the deck department include but not limited to the Master and his Chief , Second , and Third officers. The official classifications for unlicensed members of the deck department are Able Seaman and Ordinary Seaman . A common deck crew for a ship includes: A deck cadet

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936-440: A structure of rigid oxygen atoms in which hydrogen atoms flowed freely. When sandwiched between layers of graphene , ice forms a square lattice. The details of the chemical nature of liquid water are not well understood; some theories suggest that its unusual behavior is due to the existence of two liquid states. Pure water is usually described as tasteless and odorless, although humans have specific sensors that can feel

1014-412: A swimming pool when the light source is sunlight reflected from the pool's white tiles. In nature, the color may also be modified from blue to green due to the presence of suspended solids or algae. In industry, near-infrared spectroscopy is used with aqueous solutions as the greater intensity of the lower overtones of water means that glass cuvettes with short path-length may be employed. To observe

1092-493: A time, followed by protracted shore leave. However, some seamen secure jobs on ships they like and stay aboard for years. The quick turnaround of many modern ships, spending only a few hours in port, limits a seafarer's free-time ashore. Moreover, some foreign seamen entering U.S. ports from a watch list of 25 countries face restrictions on shore leave due to maritime security concerns. However, shore leave restrictions while in U.S. ports impact American seamen as well. For example,

1170-461: A variety of applications including high-temperature electrochemistry and as an ecologically benign solvent or catalyst in chemical reactions involving organic compounds. In Earth's mantle, it acts as a solvent during mineral formation, dissolution and deposition. The normal form of ice on the surface of Earth is ice I h , a phase that forms crystals with hexagonal symmetry . Another with cubic crystalline symmetry , ice I c , can occur in

1248-499: A watchkeeping license. A typical steward's department for a cargo ship would be composed of a Chief Steward , a chief cook , and a Steward's Assistant . All three positions are typically filled by unlicensed personnel. The chief steward directs, instructs, and assigns personnel performing such functions as preparing and serving meals; cleaning and maintaining officers' quarters and steward department areas; and receiving, issuing, and inventorying stores. On large passenger vessels ,

1326-422: Is intermodal or co-modal . A nation's shipping fleet (variously called merchant navy , merchant marine, or merchant fleet) consists of the ships operated by civilian crews to transport passengers or cargo from one place to another. Merchant shipping also includes water transport over the river and canal systems connecting inland destinations, large and small. For example, during the early modern era , cities in

1404-489: Is visibly blue due to absorption of light in the region c. 600–800 nm. The color can be easily observed in a glass of tap-water placed against a pure white background, in daylight. The principal absorption bands responsible for the color are overtones of the O–H stretching vibrations . The apparent intensity of the color increases with the depth of the water column, following Beer's law . This also applies, for example, with

1482-439: Is 917 kg/m (57.25 lb/cu ft), an expansion of 9%. This expansion can exert enormous pressure, bursting pipes and cracking rocks. In a lake or ocean, water at 4 °C (39 °F) sinks to the bottom, and ice forms on the surface, floating on the liquid water. This ice insulates the water below, preventing it from freezing solid. Without this protection, most aquatic organisms residing in lakes would perish during

1560-422: Is a person who is carrying out mandatory sea time to achieve their officer of the watch certificate. Their time on board is spent learning the operations and tasks of everyday life on a merchant vessel. A ship's engine department consists of the members of a ship's crew that operate and maintain the propulsion and other systems on board the vessel. Engine staff also deal with the "Hotel" facilities on board, notably

1638-589: Is an inorganic compound with the chemical formula H 2 O . It is a transparent, tasteless, odorless, and nearly colorless chemical substance . It is the main constituent of Earth 's hydrosphere and the fluids of all known living organisms (in which it acts as a solvent ). It is vital for all known forms of life , despite not providing food energy or organic micronutrients . Its chemical formula, H 2 O , indicates that each of its molecules contains one oxygen and two hydrogen atoms , connected by covalent bonds . The hydrogen atoms are attached to

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1716-493: Is at a temperature of 273.16 K (0.01 °C; 32.02 °F) and a pressure of 611.657 pascals (0.00604 atm; 0.0887 psi); it is the lowest pressure at which liquid water can exist. Until 2019 , the triple point was used to define the Kelvin temperature scale . The water/vapor phase curve terminates at 647.096 K (373.946 °C; 705.103 °F) and 22.064 megapascals (3,200.1 psi; 217.75 atm). This

1794-428: Is greater than the repulsion between the hydrogen atoms. The O–H bond length is about 0.096 nm. Other substances have a tetrahedral molecular structure, for example methane ( CH 4 ) and hydrogen sulfide ( H 2 S ). However, oxygen is more electronegative than most other elements, so the oxygen atom has a negative partial charge while the hydrogen atoms are partially positively charged. Along with

1872-487: Is important in many geological processes. Groundwater is present in most rocks , and the pressure of this groundwater affects patterns of faulting . Water in the mantle is responsible for the melt that produces volcanoes at subduction zones . On the surface of the Earth, water is important in both chemical and physical weathering processes. Water, and to a lesser but still significant extent, ice, are also responsible for

1950-470: Is it a noble gas (and therefore is not removed from the atmosphere through chemical reactions with other elements), but comparisons between the abundances of its nine stable isotopes in the modern atmosphere reveal that the Earth lost at least one ocean of water early in its history, between the Hadean and Archean eons. Any water on Earth during the latter part of its accretion would have been disrupted by

2028-498: Is known as the critical point . At higher temperatures and pressures the liquid and vapor phases form a continuous phase called a supercritical fluid . It can be gradually compressed or expanded between gas-like and liquid-like densities; its properties (which are quite different from those of ambient water) are sensitive to density. For example, for suitable pressures and temperatures it can mix freely with nonpolar compounds , including most organic compounds . This makes it useful in

2106-592: Is less critical today, the major waterways of the world including many canals are still very important and are integral parts of worldwide economies . Particularly, especially any material can be moved by water; however, water transport becomes impractical when material delivery is time-critical such as various types of perishable produce . Still, water transport is highly cost effective with regular schedulable cargoes, such as trans-oceanic shipping of consumer products – and especially for heavy loads or bulk cargos , such as coal , coke , ores , or grains . Arguably,

2184-413: Is lower than that of liquid water. In a water molecule, the hydrogen atoms form a 104.5° angle with the oxygen atom. The hydrogen atoms are close to two corners of a tetrahedron centered on the oxygen. At the other two corners are lone pairs of valence electrons that do not participate in the bonding. In a perfect tetrahedron, the atoms would form a 109.5° angle, but the repulsion between the lone pairs

2262-406: Is not surprising that the bar is now a much quieter place on most ships. In some instances games consoles are provided for the officers and crew. The officers enjoy a much higher standard of living on board ocean-going vessels. Crews are generally poorly paid, poorly qualified and have to complete contracts of approximately 9 months before returning home on leave. They often come from countries where

2340-422: Is poor at dissolving nonpolar substances. This allows it to be the " solvent of life": indeed, water as found in nature almost always includes various dissolved substances, and special steps are required to obtain chemically pure water . Water is the only common substance to exist as a solid , liquid, and gas in normal terrestrial conditions. Along with oxidane , water is one of the two official names for

2418-522: Is still popular for short trips and pleasure cruises . Transport by water is cheaper than transport by air or ground, but significantly slower for longer distances. Maritime transport accounts for roughly 80% of international trade , according to UNCTAD in 2020. Maritime transport can be realized over any distance by boat, ship, sailboat or barge , over oceans and lakes, through canals or along rivers. Shipping may be for commerce , recreation , or military purposes. While extensive inland shipping

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2496-458: Is the study of the movement, distribution, and quality of water throughout the Earth. The study of the distribution of water is hydrography . The study of the distribution and movement of groundwater is hydrogeology , of glaciers is glaciology , of inland waters is limnology and distribution of oceans is oceanography . Ecological processes with hydrology are in the focus of ecohydrology . The collective mass of water found on, under, and over

2574-1135: The Hanseatic League began taming Northern Europe 's rivers and harbors. Similarly, the Saint Lawrence Seaway connects the port cities on the Great Lakes in Canada and the United States with the Atlantic Ocean shipping routes, while the various Illinois canals connect the Great Lakes and Canada with New Orleans . Ores, coal, and grains can travel along the rivers of the American Midwest to Pittsburgh or to Birmingham , Alabama. Professional mariners are known as merchant seamen, merchant sailors, and merchant mariners, or simply seamen, sailors, or mariners. The terms "seaman" or "sailor" may also refer to

2652-484: The Industrial Revolution had its first impacts where cheap water transport by canal, navigations, or shipping by all types of watercraft on natural waterways supported cost-effective bulk transport . Containerization revolutionized maritime transport starting in the 1970s. "General cargo" includes goods packaged in boxes, cases, pallets, and barrels. When a cargo is carried in more than one mode, it

2730-554: The International Organization of Masters, Mates & Pilots notes a trend of U.S. shipping terminal operators restricting seamen from traveling from the ship to the terminal gate. Furthermore, in cases where transit is allowed, special "security fees" are at times assessed. Such restrictions on shore leave, coupled with reduced time in port, translate into longer periods at sea. Mariners report that extended periods at sea living and working with shipmates, who for

2808-485: The Moon-forming impact (~4.5 billion years ago), which likely vaporized much of Earth's crust and upper mantle and created a rock-vapor atmosphere around the young planet. The rock vapor would have condensed within two thousand years, leaving behind hot volatiles which probably resulted in a majority carbon dioxide atmosphere with hydrogen and water vapor . Afterward, liquid water oceans may have existed despite

2886-557: The Steward's Assistant , the chief cook , and other Steward's Department crewmembers. In the United States Merchant Marine , a chief steward must have a Merchant Mariner's Document issued by the United States Coast Guard . Because of international law , conventions, and agreements , all chief cooks who sail internationally are similarly documented by their respective countries. Staff officer positions on

2964-432: The elements hydrogen and oxygen by passing an electric current through it—a process called electrolysis . The decomposition requires more energy input than the heat released by the inverse process (285.8 kJ/ mol , or 15.9 MJ/kg). Liquid water can be assumed to be incompressible for most purposes: its compressibility ranges from 4.4 to 5.1 × 10  Pa in ordinary conditions. Even in oceans at 4 km depth, where

3042-529: The molar volumes of the liquid and solid phases, and L f {\displaystyle L_{\text{f}}} is the molar latent heat of melting. In most substances, the volume increases when melting occurs, so the melting temperature increases with pressure. However, because ice is less dense than water, the melting temperature decreases. In glaciers, pressure melting can occur under sufficiently thick volumes of ice, resulting in subglacial lakes . The Clausius-Clapeyron relation also applies to

3120-436: The sewage , lighting, air conditioning and water systems. They deal with bulk fuel transfers, and require training in firefighting and first aid , as well as in dealing with the ship's boats and other nautical tasks- especially with cargo loading/discharging gear and safety systems, though the specific cargo discharge function remains the responsibility of deck officers and deck workers. On LPG and LNG tankers , however,

3198-433: The water cycle consisting of the following transfer processes: Maritime transport Maritime transport (or ocean transport ) or more generally waterborne transport , is the transport of people ( passengers ) or goods ( cargo ) via waterways . Freight transport by sea has been widely used throughout recorded history . The advent of aviation has diminished the importance of sea travel for passengers, though it

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3276-449: The water cycle of evaporation , transpiration ( evapotranspiration ), condensation , precipitation, and runoff , usually reaching the sea. Water plays an important role in the world economy . Approximately 70% of the fresh water used by humans goes to agriculture . Fishing in salt and fresh water bodies has been, and continues to be, a major source of food for many parts of the world, providing 6.5% of global protein. Much of

3354-718: The 4 month mark for officers, with generous leave. Most ocean-going vessels now operate an unmanned engine room system allowing engineers to work days only. The engine room is computer controlled by night, although the duty engineer will make inspections during unmanned operation. Engineers work in a hot, humid, noisy atmosphere. Communication in the engine room is therefore by hand signals and lip-reading, and good teamwork often stands in place of any communication at all. The environmental impact of shipping includes greenhouse gas emissions , acoustic , and oil pollution . The International Maritime Organization (IMO) estimates that Carbon dioxide emissions from shipping were equal to 2.2% of

3432-753: The Catering Department is headed by the Chief Purser and managed by Assistant Pursers. Although they enjoy the benefits of having officer rank, they generally progress through the ranks to become pursers. Under the pursers are the department heads – such as chief cook, head waiter, head barman etc. They are responsible for the administration of their own areas. The chief steward also plans menus and compiles supply, overtime, and cost control records. They may requisition or purchase stores and equipment. They may bake bread, rolls, cakes, pies, and pastries. A chief steward's duties may overlap with those of

3510-444: The Earth was younger and less massive , water would have been lost to space more easily. Lighter elements like hydrogen and helium are expected to leak from the atmosphere continually, but isotopic ratios of heavier noble gases in the modern atmosphere suggest that even the heavier elements in the early atmosphere were subject to significant losses. In particular, xenon is useful for calculations of water loss over time. Not only

3588-538: The Indo-European root, with Greek ύδωρ ( ýdor ; from Ancient Greek ὕδωρ ( hýdōr ), whence English ' hydro- ' ), Russian вода́ ( vodá ), Irish uisce , and Albanian ujë . One factor in estimating when water appeared on Earth is that water is continually being lost to space. H 2 O molecules in the atmosphere are broken up by photolysis , and the resulting free hydrogen atoms can sometimes escape Earth's gravitational pull. When

3666-733: The attraction is a life unencumbered with the restraints of life ashore. Seagoing adventure and a chance to see the world also appeal to many seafarers. Whatever the calling, those who live and work at sea invariably confront social isolation. Findings by the Seafarer's International Research Center indicate a leading cause of mariners leaving the industry is "almost invariably because they want to be with their families." U.S. merchant ships typically do not allow family members to accompany seafarers on voyages. Industry experts increasingly recognize isolation, stress, and fatigue as occupational hazards. Advocacy groups such as International Labour Organization,

3744-461: The average industrial wage is still very low, such as the Philippines or India . Officers however, come from all over the world and it is not uncommon to mix the nationality of the officers on board ships. Officers are often the recipients of university degrees and have completed vast amounts of training in order to reach their rank. Officers benefit e.g. by having larger, more comfortable cabins and table service for their meals. Contracts average at

3822-577: The bent structure, this gives the molecule an electrical dipole moment and it is classified as a polar molecule . Water is a good polar solvent , dissolving many salts and hydrophilic organic molecules such as sugars and simple alcohols such as ethanol . Water also dissolves many gases, such as oxygen and carbon dioxide —the latter giving the fizz of carbonated beverages, sparkling wines and beers. In addition, many substances in living organisms, such as proteins , DNA and polysaccharides , are dissolved in water. The interactions between water and

3900-537: The boiling point, but with the liquid/gas transition the vapor phase has a much lower density than the liquid phase, so the boiling point increases with pressure. Water can remain in a liquid state at high temperatures in the deep ocean or underground. For example, temperatures exceed 205 °C (401 °F) in Old Faithful , a geyser in Yellowstone National Park . In hydrothermal vents ,

3978-545: The case of jet boats, an inboard water jet. In shallow-draft areas, such as the Everglades , some craft, such as the hovercraft , are propelled by large pusher-prop fans. Most modern merchant ships can be placed in one of a few categories, such as: Ocean liners are usually strongly built with a high freeboard to withstand rough seas and adverse conditions encountered in the open ocean, having large capacities for fuel, food and other consumables on long voyages. These were

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4056-785: The chemical compound H 2 O ; it is also the liquid phase of H 2 O . The other two common states of matter of water are the solid phase, ice , and the gaseous phase, water vapor or steam . The addition or removal of heat can cause phase transitions : freezing (water to ice), melting (ice to water), vaporization (water to vapor), condensation (vapor to water), sublimation (ice to vapor) and deposition (vapor to ice). Water differs from most liquids in that it becomes less dense as it freezes. In 1 atm pressure, it reaches its maximum density of 999.972 kg/m (62.4262 lb/cu ft) at 3.98 °C (39.16 °F), or almost 1,000 kg/m (62.43 lb/cu ft) at almost 4 °C (39 °F). The density of ice

4134-433: The desired result. Conversely, a pressure cooker can be used to decrease cooking times by raising the boiling temperature. In a vacuum, water will boil at room temperature. On a pressure/temperature phase diagram (see figure), there are curves separating solid from vapor, vapor from liquid, and liquid from solid. These meet at a single point called the triple point , where all three phases can coexist. The triple point

4212-539: The engine and deck departments work four hours on then have eight hours off watch keeping. However, there are many overtime jobs to be done daily. This cycle repeats endlessly, 24 hours a day while the ship is at sea. Members of the steward department typically are day workers who put in at least eight-hour shifts. Operations at sea, including repairs, safeguarding against piracy , securing cargo, underway replenishment , and other duties provide opportunities for overtime work. Service aboard ships typically extends for months at

4290-404: The engine department. Mariners spend much of their life beyond the reach of land. They sometimes face dangerous conditions at sea or on lakes – the fishing port of Gloucester, Massachusetts has a seaside memorial listing over 10,000 fishermen who lost their lives to the sea, and the Great Lakes have seen over 10,000 lost vessels since the 1800s, yet men and women still go to sea. For some,

4368-486: The force of gravity . This property is relied upon by all vascular plants , such as trees. Water is a weak solution of hydronium hydroxide—there is an equilibrium 2H 2 O ⇌ H 3 O + OH , in combination with solvation of the resulting hydronium and hydroxide ions. Pure water has a low electrical conductivity , which increases with the dissolution of a small amount of ionic material such as common salt . Liquid water can be split into

4446-479: The form of snow . The gaseous state of water is steam or water vapor . Water covers about 71% of the Earth's surface, with seas and oceans making up most of the water volume (about 96.5%). Small portions of water occur as groundwater (1.7%), in the glaciers and the ice caps of Antarctica and Greenland (1.7%), and in the air as vapor , clouds (consisting of ice and liquid water suspended in air), and precipitation (0.001%). Water moves continually through

4524-450: The fundamental stretching absorption spectrum of water or of an aqueous solution in the region around 3,500 cm (2.85 μm) a path length of about 25 μm is needed. Also, the cuvette must be both transparent around 3500 cm and insoluble in water; calcium fluoride is one material that is in common use for the cuvette windows with aqueous solutions. The Raman-active fundamental vibrations may be observed with, for example,

4602-412: The global human-made emissions in 2012 and expects them to rise 50 to 250 percent by 2050 if no action is taken. The IEA forecasts that ammonia will meet approximately 45% of shipping fuel demands by 2050. For a port to efficiently send and receive cargo, it requires infrastructure : docks, bollards, pilings, cranes, bulk cargo handling equipment, and so on – equipment and organization supporting

4680-416: The liquid is known as boiling ). Sublimation and deposition also occur on surfaces. For example, frost is deposited on cold surfaces while snowflakes form by deposition on an aerosol particle or ice nucleus. In the process of freeze-drying , a food is frozen and then stored at low pressure so the ice on its surface sublimates. The melting and boiling points depend on pressure. A good approximation for

4758-753: The liquid or solid state can form up to four hydrogen bonds with neighboring molecules. Hydrogen bonds are about ten times as strong as the Van der Waals force that attracts molecules to each other in most liquids. This is the reason why the melting and boiling points of water are much higher than those of other analogous compounds like hydrogen sulfide. They also explain its exceptionally high specific heat capacity (about 4.2 J /(g·K)), heat of fusion (about 333 J/g), heat of vaporization ( 2257 J/g ), and thermal conductivity (between 0.561 and 0.679 W/(m·K)). These properties make water more effective at moderating Earth's climate , by storing heat and transporting it between

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4836-1070: The long-distance trade of commodities (such as oil, natural gas, and manufactured products) is transported by boats through seas, rivers, lakes, and canals. Large quantities of water, ice, and steam are used for cooling and heating in industry and homes. Water is an excellent solvent for a wide variety of substances, both mineral and organic; as such, it is widely used in industrial processes and in cooking and washing. Water, ice, and snow are also central to many sports and other forms of entertainment, such as swimming , pleasure boating, boat racing , surfing , sport fishing , diving , ice skating , snowboarding , and skiing . The word water comes from Old English wæter , from Proto-Germanic * watar (source also of Old Saxon watar , Old Frisian wetir , Dutch water , Old High German wazzar , German Wasser , vatn , Gothic 𐍅𐌰𐍄𐍉 ( wato )), from Proto-Indo-European * wod-or , suffixed form of root * wed- ( ' water ' ; ' wet ' ). Also cognate , through

4914-601: The main stay of most passenger transport companies, however, due to the growth of air travel, the passenger ships saw a steady decline. Cruise ships later filled the void and are primarily used by people who still have a love of the sea and offer more amenities than the older passenger ships. A cargo ship sailing from a European port to a US one will typically take 10–12 days depending on water currents and other factors. In order to make container ship transport more economical, ship operators sometimes reduce cruising speed, thereby increasing transit time, to reduce fuel consumption,

4992-443: The most part are strangers, takes getting used to. At the same time, there is an opportunity to meet people from other ethnic and cultural backgrounds. Recreational opportunities have improved aboard some U.S. ships, which may feature gyms and day rooms for watching movies, swapping sea stories , and other activities. And in some cases, especially tankers, it is possible for a mariner to be accompanied by members of his family. However,

5070-418: The oceans and the atmosphere. The hydrogen bonds of water are around 23 kJ/mol (compared to a covalent O-H bond at 492 kJ/mol). Of this, it is estimated that 90% is attributable to electrostatics, while the remaining 10% is partially covalent. These bonds are the cause of water's high surface tension and capillary forces. The capillary action refers to the tendency of water to move up a narrow tube against

5148-538: The oceans may have always been on the Earth since the beginning of the planet's formation . Water ( H 2 O ) is a polar inorganic compound . At room temperature it is a tasteless and odorless liquid , nearly colorless with a hint of blue . The simplest hydrogen chalcogenide , it is by far the most studied chemical compound and is sometimes described as the "universal solvent" for its ability to dissolve more substances than any other liquid, though it

5226-488: The oxygen atom at an angle of 104.45°. In liquid form, H 2 O is also called "water" at standard temperature and pressure . Because Earth's environment is relatively close to water's triple point , water exists on Earth as a solid , a liquid , and a gas . It forms precipitation in the form of rain and aerosols in the form of fog . Clouds consist of suspended droplets of water and ice , its solid state. When finely divided, crystalline ice may precipitate in

5304-402: The presence of water in their mouths, and frogs are known to be able to smell it. However, water from ordinary sources (including mineral water ) usually has many dissolved substances that may give it varying tastes and odors. Humans and other animals have developed senses that enable them to evaluate the potability of water in order to avoid water that is too salty or putrid . Pure water

5382-437: The pressure is 400 atm, water suffers only a 1.8% decrease in volume. The viscosity of water is about 10 Pa· s or 0.01 poise at 20 °C (68 °F), and the speed of sound in liquid water ranges between 1,400 and 1,540 metres per second (4,600 and 5,100 ft/s) depending on temperature. Sound travels long distances in water with little attenuation , especially at low frequencies (roughly 0.03 dB /km for 1 k Hz ),

5460-587: The rate of change of the melting temperature with pressure is given by the Clausius–Clapeyron relation : d T d P = T ( v L − v S ) L f {\displaystyle {\frac {dT}{dP}}={\frac {T\left(v_{\text{L}}-v_{\text{S}}\right)}{L_{\text{f}}}}} where v L {\displaystyle v_{\text{L}}} and v S {\displaystyle v_{\text{S}}} are

5538-413: The subunits of these biomacromolecules shape protein folding , DNA base pairing , and other phenomena crucial to life ( hydrophobic effect ). Many organic substances (such as fats and oils and alkanes ) are hydrophobic , that is, insoluble in water. Many inorganic substances are insoluble too, including most metal oxides , sulfides , and silicates . Because of its polarity, a molecule of water in

5616-488: The surface of a planet is called the hydrosphere . Earth's approximate water volume (the total water supply of the world) is 1.386 billion cubic kilometres (333 million cubic miles). Liquid water is found in bodies of water , such as an ocean, sea, lake, river, stream, canal , pond, or puddle . The majority of water on Earth is seawater . Water is also present in the atmosphere in solid, liquid, and vapor states. It also exists as groundwater in aquifers . Water

5694-537: The surface temperature of 230 °C (446 °F) due to the increased atmospheric pressure of the CO 2 atmosphere. As the cooling continued, most CO 2 was removed from the atmosphere by subduction and dissolution in ocean water, but levels oscillated wildly as new surface and mantle cycles appeared. Geological evidence also helps constrain the time frame for liquid water existing on Earth. A sample of pillow basalt (a type of rock formed during an underwater eruption)

5772-403: The temperature can exceed 400 °C (752 °F). At sea level , the boiling point of water is 100 °C (212 °F). As atmospheric pressure decreases with altitude, the boiling point decreases by 1 °C every 274 meters. High-altitude cooking takes longer than sea-level cooking. For example, at 1,524 metres (5,000 ft), cooking time must be increased by a fourth to achieve

5850-458: The upper atmosphere. As the pressure increases, ice forms other crystal structures . As of 2024, twenty have been experimentally confirmed and several more are predicted theoretically. The eighteenth form of ice, ice XVIII , a face-centred-cubic, superionic ice phase, was discovered when a droplet of water was subject to a shock wave that raised the water's pressure to millions of atmospheres and its temperature to thousands of degrees, resulting in

5928-441: The winter. Water is a diamagnetic material. Though interaction is weak, with superconducting magnets it can attain a notable interaction. At a pressure of one atmosphere (atm), ice melts or water freezes (solidifies) at 0 °C (32 °F) and water boils or vapor condenses at 100 °C (212 °F). However, even below the boiling point, water can change to vapor at its surface by evaporation (vaporization throughout

6006-458: Was also a radio department, headed by a chief radio officer and supported by a number of radio officers. Since the introduction of GMDSS (Satellite communications) and the subsequent exemptions from carrying radio officers if the vessel is so equipped, this department has fallen away, although many ships do still carry specialist radio officers, particularly passenger vessels. Many radio officers became 'electro-technical officers', and transferred into

6084-809: Was recovered from the Isua Greenstone Belt and provides evidence that water existed on Earth 3.8 billion years ago. In the Nuvvuagittuq Greenstone Belt , Quebec, Canada, rocks dated at 3.8 billion years old by one study and 4.28 billion years old by another show evidence of the presence of water at these ages. If oceans existed earlier than this, any geological evidence has yet to be discovered (which may be because such potential evidence has been destroyed by geological processes like crustal recycling ). More recently, in August 2020, researchers reported that sufficient water to fill

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