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Diver Navigation
Diver navigation, termed "underwater navigation" by scuba divers, is a set of techniques—including observing natural features, the use of a compass, and surface observations—that divers use to navigate underwater. Free-divers do not spend enough time underwater for navigation to be important, and surface supplied divers are limited in the distance they can travel by the length of their umbilicals and are usually directed from the surface control point. On those occasions when they need to navigate they can use the same methods used by scuba divers. Although it is considered a basic skill, it is normally only taught to a limited degree as part of basic Open Water certification. Most North American diver training agencies only teach significant elements of underwater navigation as part of the Advanced Open Water Diver certification program. Underwater navigation is usually a core component of most, if not all, advanced recreational diver training. In the PADI Advanced ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UW Navigation Tools
UW, U.W., ''Uw'', or uw may refer to: Universities Canada * University of Waterloo * University of Windsor * University of Winnipeg United States * University of Washington * University of Wisconsin System * University of Wisconsin–La Crosse * University of Wisconsin–Madison * University of Wisconsin–Milwaukee * University of Wyoming Other countries * University of Warsaw, Poland * University of Wuppertal, Germany * University of Würzburg, Germany Other uses * uw (digraph) * ''Uw'', the international symbol for relative humidity * Unconventional warfare * Unconventional warfare (United States), a US-specific definition of unconventional warfare used by its Department of Defense * ''Unia Wolnosci'' (Freedom Union), a Polish political party See also * WU (other) Wu may refer to: States and regions on modern China's territory *Wu (state) (; och, *, italic=yes, links=no), a kingdom during the Spring and Autumn Period 771–476 BCE ** Suzhou or Wu (), its eponymo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distance Line
A distance line, penetration line, cave line or guide line is an item of diving equipment used by scuba divers as a means of returning to a safe starting point in conditions of low visibility, water currents or where pilotage is difficult. They are often used in cave diving and wreck diving where the diver must return to open water after a penetration when it may be difficult to discern the return route. Guide lines are also useful in the event of silt out. Distance lines are wound on to a spool or a reel. The length of the distance line used is dependent on the plan for the dive. An open water diver using the distance line only for a surface marker buoy may only need , whereas a cave diver may use multiple reels of lengths from to 1000+ ft (300 m). Reels for distance lines may have a locking mechanism, ratchet or adjustable drag to control deployment of the line and a winding handle to help keep slack line under control and rewind line. Lines are used in open water ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecological Zone
Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps with the closely related sciences of biogeography, evolutionary biology, genetics, ethology, and natural history. Ecology is a branch of biology, and it is not synonymous with environmentalism. Among other things, ecology is the study of: * The abundance, biomass, and distribution of organisms in the context of the environment * Life processes, antifragility, interactions, and adaptations * The movement of materials and energy through living communities * The successional development of ecosystems * Cooperation, competition, and predation within and between species * Patterns of biodiversity and its effect on ecosystem processes Ecology has practical applications in conservation biology, wetland management, natural resource management (ag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strike And Dip
Strike and dip is a measurement convention used to describe the orientation, or attitude, of a planar geologic feature. A feature's strike is the azimuth of an imagined horizontal line across the plane, and its dip is the angle of inclination measured downward from horizontal. They are used together to measure and document a structure's characteristics for study or for use on a geologic map. A feature's orientation can also be represented by dip and dip direction, using the azimuth of the dip rather than the strike value. Linear features are similarly measured with trend and plunge, where "trend" is analogous to dip direction and "plunge" is the dip angle. Strike and dip are measured using a compass and a clinometer. A compass is used to measure the feature's strike by holding the compass horizontally against the feature. A clinometer measures the features dip by recording the inclination perpendicular to the strike. These can be done separately, or together using a tool such a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glossary Of Underwater Diving Terminology
This is a glossary of technical terms, jargon, diver slang and acronyms used in underwater diving. The definitions listed are in the context of underwater diving. There may be other meanings in other contexts. Underwater diving can be described as a human activity Human behavior is the potential and expressed capacity ( mentally, physically, and socially) of human individuals or groups to respond to internal and external stimuli throughout their life. Kagan, Jerome, Marc H. Bornstein, and Richard M. ... – intentional, purposive, conscious and subjectively meaningful sequence of actions. Underwater diving is practiced as part of an occupation, or for recreation, where the practitioner submerges below the surface of the water or other liquid for a period which may range between seconds to the order of a day at a time, either exposed to the ambient pressure or isolated by a pressure resistant suit, to interact with the underwater environment for pleasure, competiti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tide
Tides are the rise and fall of sea levels caused by the combined effects of the gravity, gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another. Tide tables can be used for any given locale to find the predicted times and amplitude (or "tidal range"). The predictions are influenced by many factors including the alignment of the Sun and Moon, the #Phase and amplitude, phase and amplitude of the tide (pattern of tides in the deep ocean), the amphidromic systems of the oceans, and the shape of the coastline and near-shore bathymetry (see ''#Timing, Timing''). They are however only predictions, the actual time and height of the tide is affected by wind and atmospheric pressure. Many shorelines experience semi-diurnal tides—two nearly equal high and low tides each day. Other locations have a diurnal cycle, diurnal tide—one high and low tide each day. A "mixed tide"—two uneven magnitude ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ocean Current
An ocean current is a continuous, directed movement of sea water generated by a number of forces acting upon the water, including wind, the Coriolis effect, breaking waves, cabbeling, and temperature and salinity differences. Depth contours, shoreline configurations, and interactions with other currents influence a current's direction and strength. Ocean currents are primarily horizontal water movements. An ocean current flows for great distances and together they create the global conveyor belt, which plays a dominant role in determining the climate of many of Earth’s regions. More specifically, ocean currents influence the temperature of the regions through which they travel. For example, warm currents traveling along more temperate coasts increase the temperature of the area by warming the sea breezes that blow over them. Perhaps the most striking example is the Gulf Stream, which makes northwest Europe much more temperate for its high latitude compared to other areas at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guide Line
A distance line, penetration line, cave line or guide line is an item of diving equipment used by scuba divers as a means of returning to a safe starting point in conditions of low visibility, water currents or where pilotage is difficult. They are often used in cave diving and wreck diving where the diver must return to open water after a penetration when it may be difficult to discern the return route. Guide lines are also useful in the event of silt out. Distance lines are wound on to a spool or a reel. The length of the distance line used is dependent on the plan for the dive. An open water diver using the distance line only for a surface marker buoy may only need , whereas a cave diver may use multiple reels of lengths from to 1000+ ft (300 m). Reels for distance lines may have a locking mechanism, ratchet or adjustable drag to control deployment of the line and a winding handle to help keep slack line under control and rewind line. Lines are used in open water ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diving Equipment
Diving equipment is equipment used by underwater divers to make diving activities possible, easier, safer and/or more comfortable. This may be equipment primarily intended for this purpose, or equipment intended for other purposes which is found to be suitable for diving use. The fundamental item of diving equipment used by divers other than freedivers, is underwater breathing apparatus, such as scuba equipment, and surface-supplied diving equipment, but there are other important items of equipment that make diving safer, more convenient or more efficient. Diving equipment used by recreational scuba divers, also known as scuba gear, is mostly personal equipment carried by the diver, but professional divers, particularly when operating in the surface supplied or saturation mode, use a large amount of support equipment not carried by the diver. Equipment which is used for underwater work or other activities which is not directly related to the activity of diving, or which has n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shot Line
A diving shot line, shot line, or diving shot, a type of Downline (diving), downline or descending line (US Navy), is an item of diving equipment consisting of a Ballast, ballast weight (the shot), a Rope, line and a buoy. The weight is dropped on the dive site. The line connects the weight and the buoy and is used by divers to as a visual and tactile reference to move between the surface and the dive site more safely and more easily, and as a controlled position for in-water staged decompression stops. It may also be used to physically control rate of descent and ascent, particularly by Surface supplied diving, surface-supplied divers. A "lazy shot" is a shot which is suspended above the bottom. It may be tethered to the main shot line at a convenient depth. It is used for decompression and frees the main shot line for other divers. The lazy shot's line does not need to be longer than the decompression depth and is often only deep enough for the longer stops. It only n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impeller Log
An impeller or impellor is a rotor used to increase the pressure and flow of a fluid. It is the opposite of a turbine, which extracts energy from, and reduces the pressure of, a flowing fluid. In pumps An impeller is a rotating component of a centrifugal pump that accelerates fluid outward from the center of rotation, thus transferring energy from the motor that drives the pump to the fluid being pumped. The velocity achieved by the impeller transfers into pressure when the outward movement of the fluid is confined by the pump casing. An impeller is usually a short cylinder with an open inlet (called an eye) to accept incoming fluid, vanes to push the fluid radially, and a splined, keyed, or threaded bore to accept a drive shaft. It can be cheaper to cast an impeller and its spindle as one piece, rather than separately. This combination is sometimes referred to simply as the "rotor." Types Open impellers An open impeller has a hub with attached vanes and is mounted on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pilotage
Piloting or pilotage is the process of navigating on water or in the air using fixed points of reference on the sea or on land, usually with reference to a nautical chart or aeronautical chart to obtain a fix of the position of the vessel or aircraft with respect to a desired course or location. Horizontal fixes of position from known reference points may be obtained by sight or by radar. Vertical position may be obtained by depth sounder to determine depth of the water body below a vessel or by altimeter to determine an aircraft's altitude, from which its distance above the ground can be deduced. Piloting a vessel is usually practiced close to shore or on inland waterways. Pilotage of an aircraft is practiced under visual meteorological conditions for flight. Land navigation is a related discipline, using a topographic map, especially when applied over trackless terrain. Divers use related techniques for underwater navigation. Piloting references Charts Depending on wheth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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