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Helicopter Turn
Finning techniques are the skills and methods used by swimmers and underwater divers to propel themselves through the water and to maneuver when wearing swimfins. There are several styles used for propulsion, some of which are more suited to particular swimfin configurations. There are also techniques for positional maneuvering, such as rotation on the spot, which may not involve significant locational change. Use of the most appropriate finning style for the circumstances can increase propulsive efficiency, reduce fatigue, improve precision of maneuvering and control of the diver's position in the water, and thereby increase the task effectiveness of the diver and reduce the impact on the environment. Propulsion through water requires much more work than through air due to higher density and viscosity. Diving equipment which is bulky usually increases drag, and reduction of drag can significantly reduce the effort of finning. This can be done to some extent by streamlining diving ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DIR Divers Sandra Edwards 2010
Dir, dir, or DIR may refer to: Acronyms * ''De Imperatoribus Romanis'', an online biographical encyclopedia of the Roman emperors from 27 BC to 1453 AD * Detroit International Riverfront, an area of Detroit, Michigan in the United States * Developmental, Individual differences, Relationship-based approach, a developmental intervention to autism * Digitally Imported Radio, an internet radio station * Digital Instrumentation Recorder, a magnetic tape format by Sony * Doing It Right (scuba diving), Doing It Right, a methodology for scuba diving * Double inversion recovery, an MRI sequence In computing * An abbreviation for directory (file systems) * dir (command), a shell command * directory (OpenVMS command), an operating system command * , an HTML element#dir, HTML element Places and areas * Dir, Pakistan, a town in the Khyber Pakhtunkhwa province of Pakistan * Dir (union council), an administrative unit in the Khyber Pakhtunkhwa province of Pakistan * Dir (princely state), a fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cave Diving
Cave-diving is underwater diving in water-filled caves. It may be done as an extreme sport, a way of exploring flooded caves for scientific investigation, or for the underwater search and recovery, search for and recovery of divers or, as in the Tham Luang cave rescue, 2018 Thai cave rescue, other cave users. The equipment used varies depending on the circumstances, and ranges from Free-diving, breath hold to Surface-supplied diving, surface supplied, but almost all cave-diving is done using scuba equipment, often in specialised configurations with engineering redundancy, redundancies such as Sidemount diving, sidemount or backmounted twinset. Recreational cave-diving is generally considered to be a type of technical diving due to the lack of a free surface during large parts of the dive, and often involves planned Decompression (diving), decompression stops. A distinction is made by recreational diver training agencies between cave-diving and cavern-diving, where cavern diving i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flutter Kick
The flutter kick is a kicking movement used in both swimming and calisthenics. Swimming In swimming, the flutter kick refers to an alternating up and down movement of the legs. It is seen in front crawl and backstroke. The downbeat refers to the portion of each individual kick where the leg moves downwards, and the upbeat refers to the repositioning of the leg upwards. In front crawl, the flutter kick is sometimes referred to as the front crawl kick, and in backstroke it is sometimes called the backstroke kick. Phases In front crawl, the downbeat of each kick is initiated by the simultaneous action of bending the knee and flexing the hip to push down on the water with the thigh. The knee then extends forcefully, pushing the lower leg against the water until the leg is straight. The ankle then extends, pushing the foot into the water until it is inline with the rest of the leg. When the knee extends for the downbeat, it also has the effect of lifting the thigh and initiating t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicopter Turns
A helicopter is a type of rotorcraft in which Lift (force), lift and thrust are supplied by horizontally spinning Helicopter rotor, rotors. This allows the helicopter to VTOL, take off and land vertically, to hover (helicopter), hover, and to fly forward, backward and laterally. These attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft and many forms of short take-off and landing (STOL) or short take-off and vertical landing (STOVL) aircraft cannot perform without a runway. The Focke-Wulf Fw 61 was the first successful, practical, and fully controllable helicopter in 1936, while in 1942, the Sikorsky R-4 became the first helicopter to reach full-scale mass production, production. Starting in 1939 and through 1943, Igor Sikorsky worked on the development of the Vought-Sikorsky VS-300, VS-300, which over four iterations, became the basis for modern helicopters with a single main rotor and a single tail rotor. Although most earlier ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backward Kick
Backward or Backwards is a relative direction. Backwards may also refer to: * Anadrome, a term created from another word spelled backwards * "Backwards" (''Red Dwarf''), episode of sci-fi TV sitcom ''Red Dwarf'' ** ''Backwards'' (novel), a novel based on the episode * '' Backwards: The Riddle of Dyslexia'', 1984 American TV program * "Backwards" (Rascal Flatts song), a 2006 country music song on ''Me and My Gang'' * "Backwards", a song by Apartment 26 from the '' Mission: Impossible 2 (soundtrack)'' * "Backward", a song by Quicksand from the album ''Manic Compression'' * Backmasking, a recording technique in which a sound or message is recorded backward onto a track that is meant to be played forward See also * Other Backward Class, a collective term used by the Government of India to classify castes which are educationally or socially disadvantaged * * * * * " Sdrawkcab" (an anadrome An anadrome, also known as an Emordnilap or a Semordnilap is a word or phrase whose letter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monofin
A monofin is a type of swimfin typically used in underwater sports such as finswimming, free-diving and underwater orienteering. It consists of a single or linked surfaces attached to both of the diver's feet, emulating the fluke of Cetaceans like whales or porpoises. Even though the diver's appearance might be reminiscent of a mermaid or merman, monofin swimming is not the same as mermaiding. The arrival of the monofin in the early 1970s led to the breaking of all finswimming world records by the end of the decade due to the improved performance possible when used instead of two ordinary swimfins. Use To differentiate between the use of monofins and conventional fins, the latter are sometimes referred to as stereo fins or bi-fins. The monofin swimmer extends arms forward, locking hands together, locking the head between the biceps, in a position known as streamline position. The undulating movement starts in the shoulders, with maximum amplitude towards the hips; the le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swimfin
Swimfins, swim fins, diving fins, or flippers are finlike accessories worn on the feet, legs or hands and made from rubber, plastic, carbon fiber or combinations of these materials, to aid movement through the water in water sports activities such as swimming, bodyboarding, bodysurfing, float-tube fishing, kneeboarding, riverboarding, scuba diving, snorkeling, spearfishing, underwater hockey, underwater rugby and various other types of underwater diving. Swimfins help the wearer to move through water more efficiently, as human feet are too small and inappropriately shaped to provide much thrust, especially when the wearer is carrying equipment that increases hydrodynamic drag. Very long fins and monofins used by freedivers as a means of underwater propulsion do not require high-frequency leg movement. This improves efficiency and helps to minimize oxygen consumption. Short, stiff-bladed fins are effective for short bursts of acceleration and maneuvering, and are useful fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silt
Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension (chemistry), suspension with water. Silt usually has a floury feel when dry, and lacks Plasticity (physics), plasticity when wet. Silt can also be felt by the tongue as granular when placed on the front teeth (even when mixed with clay particles). Silt is a common material, making up 45% of average modern mud. It is found in many river deltas and as wind-deposited accumulations, particularly in central Asia, north China, and North America. It is produced in both very hot climates (through such processes as collisions of quartz grains in dust storms) and very cold climates (through such processes as glacial grinding of quartz grains.) Loess is soil rich in silt which makes up some of the most fertile agricultural land on Earth. However, silt is very vulnerable to erosion, and it has poo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolphin Kick
The dolphin kick is a kicking movement used in swimming. It is frequently used by competitive swimmers during entry and turns, and as part of the butterfly stroke. Description The dolphin kick is named for its resemblance to the motions made by a swimming dolphin. It is typically used in Swimming (sport), competitive swimming immediately after a swimmer enters the water or after turns. The swimmer performs the kick by moving both legs together, vertically, which sends a wave through the swimmer's body, propelling them forward. The stroke is useful in competitive swimming for its physical properties: it reduces Drag (physics), drag while providing a significant amount of thrust, with comparatively low physical exertion. In competitive breaststroke swimming, a single dolphin kick is allowed before the breaststroke pullout at the start and each turn, and it must be performed before the first breaststroke kick. This kick should occur after the swimmer leaves the wall and before the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flutter Kick
The flutter kick is a kicking movement used in both swimming and calisthenics. Swimming In swimming, the flutter kick refers to an alternating up and down movement of the legs. It is seen in front crawl and backstroke. The downbeat refers to the portion of each individual kick where the leg moves downwards, and the upbeat refers to the repositioning of the leg upwards. In front crawl, the flutter kick is sometimes referred to as the front crawl kick, and in backstroke it is sometimes called the backstroke kick. Phases In front crawl, the downbeat of each kick is initiated by the simultaneous action of bending the knee and flexing the hip to push down on the water with the thigh. The knee then extends forcefully, pushing the lower leg against the water until the leg is straight. The ankle then extends, pushing the foot into the water until it is inline with the rest of the leg. When the knee extends for the downbeat, it also has the effect of lifting the thigh and initiating t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frontal Plane
The dorsal plane (also known as the coronal plane or frontal plane, especially in human anatomy) is an anatomical plane that divides the body into dorsal and ventral sections. It is perpendicular to the sagittal and transverse planes. Human anatomy The coronal plane is an example of a longitudinal plane. For a human, the mid-coronal plane would transect a standing body into two halves (front and back, or anterior and posterior) in an imaginary line that cuts through both shoulders. The sternal plane (''planum sternale'') is a coronal plane which transects the front of the sternum. Etymology The term is derived from Latin ''corona'' ('garland, crown'), from Ancient Greek κορώνη (''korōnē'', 'garland, wreath'). The coronal plane is so called because it lies in the same direction as the coronal suture. Additional images File:Coronal plane CT scan of the paranasal sinuses illustrative image.jpg, CT scan of the paranasal sinuses with coronal reconstruction (right) and axi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breaststroke
Breaststroke is a human swimming, swimming style in which the swimmer is on their chest and the torso does not rotate. It is the most popular recreational style due to the swimmer's head being out of the water a large portion of the time, and that it can be swum comfortably at slow speeds. In most swimming classes, beginners learn either the breaststroke or the freestyle (front crawl) first. However, at the competitive level, swimming breaststroke at speed requires endurance and strength comparable to other strokes. Some people refer to breaststroke as the "frog" stroke, as the arms and legs move somewhat like a frog swimming in the water. The stroke itself is the slowest of any competitive strokes and is thought to be the oldest of all swimming strokes. Speed and ergonomics Breaststroke is the slowest of the four official styles in swimming (sport), competitive swimming. The fastest breaststrokers can swim about 1.70 meters (~5.6 feet) per second. It is sometimes the harde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
