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Bottom Gas
Scuba gas planning is the aspect of dive planning and of gas management which deals with the calculation or estimation of the amounts and mixtures of gases to be used for a planned dive. It may assume that the dive profile, including decompression, is known, but the process may be iterative, involving changes to the dive profile as a consequence of the gas requirement calculation, or changes to the gas mixtures chosen. Use of calculated reserves based on planned dive profile and estimated gas consumption rates rather than an arbitrary pressure is sometimes referred to as rock bottom gas management. The purpose of gas planning is to ensure that for all reasonably foreseeable contingencies, the divers of a team have sufficient breathing gas to safely return to a place where more breathing gas is available. In almost all cases this will be the surface. Gas planning includes the following aspects: * Choice of breathing gases * Choice of scuba configuration * Estimation of gas req ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decompression Dive-Preparation
Decompression has several meanings, some of which are covered by several articles: * Data decompression, the action of reversing data compression * Decompression (physics), the release of pressure and the opposition of compression (physical), physical compression ** Decompression (altitude). the reduction of pressure and the related physiological effects due to increase in altitude or other equivalent reduction of ambient pressure below normal atmospheric pressure ** Uncontrolled decompression, catastrophic reduction of pressure in accidents involving pressure vessels such as aircraft ** Decompression (diving), the reduction in pressure and the process of allowing dissolved inert gases to be eliminated from the tissues during ascent from a dive. Also relating to decompression (diving): *** Decompression algorithm, or decompression model. One of several algorithms or theoretical models used to compute decompression tables, or the decompression status of a diver in real-time using a di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygen Toxicity
Oxygen toxicity is a condition resulting from the harmful effects of breathing molecular oxygen () at increased partial pressures. Severe cases can result in cell damage and death, with effects most often seen in the central nervous system, lungs, and eyes. Historically, the central nervous system condition was called the Paul Bert effect, and the pulmonary condition the Lorrain Smith effect, after the researchers who pioneered the discoveries and descriptions in the late 19th century. Oxygen toxicity is a concern for underwater divers, those on high concentrations of supplemental oxygen (particularly premature babies), and those undergoing hyperbaric oxygen therapy. The result of breathing increased partial pressures of oxygen is hyperoxia, an excess of oxygen in body tissues. The body is affected in different ways depending on the type of exposure. Central nervous system toxicity is caused by short exposure to high partial pressures of oxygen at greater than atmospheric pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rule Of Thumb
In English, the phrase ''rule of thumb'' refers to an approximate method for doing something, based on practical experience rather than theory. This usage of the phrase can be traced back to the 17th century and has been associated with various trades where quantities were measured by comparison to the width or length of a thumb. A modern folk etymology holds that the phrase is derived from the maximum width of a stick allowed for wife-beating under English common law, but no such law ever existed. This belief may have originated in a rumored statement by 18th-century judge Sir Francis Buller that a man may beat his wife with a stick no wider than his thumb. The rumor produced numerous jokes and satirical cartoons at Buller's expense, but there is no record that he made such a statement. English jurist Sir William Blackstone wrote in his ''Commentaries on the Laws of England'' of an "old law" that once allowed "moderate" beatings by husbands, but he did not mention thumbs or any ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Submersible Pressure Gauge
A diving regulator is a pressure regulator that controls the pressure of breathing gas for diving. The most commonly recognised application is to reduce pressurized breathing gas to ambient pressure and deliver it to the diver, but there are also other types of gas pressure regulator used for diving applications. The gas may be air or one of a variety of specially blended breathing gases. The gas may be supplied from a scuba cylinder carried by the diver or via a hose from a compressor or high-pressure storage cylinders at the surface in surface-supplied diving. A gas pressure regulator has one or more valves in series which reduce pressure from the source, and use the downstream pressure as feedback to control the delivered pressure, or the upstream pressure as feedback to prevent excessive flow rates, lowering the pressure at each stage. The terms "regulator" and "demand valve" are often used interchangeably, but a demand valve is the final stage pressure-reduction regulator ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pony Cylinder
A pony bottle is a small diving cylinder which is fitted with an independent regulator, and carried by a scuba diver as an extension to the scuba set. In an emergency, such as depletion of the diver's main air supply, it can be used as an alternative air source or bailout bottle to allow a normal ascent in place of a controlled emergency swimming ascent. The key attribute of a pony bottle is that it provides a totally independent and redundant source of breathing gas for the diver. The name ''pony'' is due to the smaller size, often of only a few litres capacity. Pony bottles are used by divers who understand that no matter their preparation and planning, accidents may happen, and cannot, or do not choose to depend on another diver for emergency breathing gas. They are carried by the diver in one of several alternative configurations, and the capacity and contents should be sufficient to allow a safe ascent from any point in the planned dive profile. Configuration In a pony ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bailout Bottle
A bailout bottle (BoB) or, more formally, bailout cylinder is a scuba cylinder carried by an underwater diver for use as an emergency supply of breathing gas in the event of a primary gas supply failure. A bailout cylinder may be carried by a scuba diver in addition to the primary scuba set, or by a surface supplied diver using either free-flow or demand systems. The bailout gas is not intended for use during the dive except in an emergency, and would be considered a fully redundant breathing gas supply if used correctly. The term may refer to just the cylinder, or the bailout set or emergency gas supply (EGS), which is the cylinder with the gas delivery system attached. The bailout set or bailout system is the combination of the emergency gas cylinder with the gas delivery system to the diver, which includes a diving regulator with either a demand valve, a bailout block, or a bailout valve (BOV). In solo diving, a buddy bottle is a bailout cylinder carried as a substitute for an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rebreather
A rebreather is a breathing apparatus that absorbs the carbon dioxide of a user's breathing, exhaled breath to permit the rebreathing (recycling) of the substantially unused oxygen content, and unused inert content when present, of each breath. Oxygen is added to replenish the amount metabolised by the user. This differs from open-circuit breathing apparatus, where the exhaled gas is discharged directly into the environment. The purpose is to extend the breathing endurance of a limited gas supply, and, for covert military use by frogmen or observation of underwater life, eliminating the bubbles produced by an open circuit system and in turn not scaring wildlife being filmed. A rebreather is generally understood to be a portable unit carried by the user. The same technology on a vehicle or non-mobile installation is more likely to be referred to as a life-support system. Rebreather technology may be used where breathing gas supply is limited, such as underwater or in space, where ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Top View Of Sidemount Diver DSC 0078 Photo By Pete Nawrocky
A spinning top, or simply a top, is a toy with a squat body and a sharp point at the bottom, designed to be spun on its vertical axis, balancing on the tip due to the gyroscopic effect. Once set in motion, a top will usually wobble for a few seconds, spin upright for a while, then start to wobble again with increasing amplitude as it loses energy, and finally tip over and roll on its side. Tops exist in many variations and materials, chiefly wood, metal, and plastic, often with a metal tip. They may be set in motion by twirling a handle with the fingers, by pulling a rope coiled around the body, or by means of a built-in auger (spiral plunger). Such toys have been used since antiquity in solitary or competitive games, where each player tries to keep one's top spinning for as long as possible, or achieve some other goal. Some tops have faceted bodies with symbols or inscriptions, and are used like dice to inject randomness into games, or for divination and ritual purposes. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diver Using Inspiration Rebreather At The Wreck Of The MV Orotava P6308046
Diver or divers may refer to: *Diving (sport), the sport of performing acrobatics while jumping or falling into water *Practitioner of underwater diving, including: **scuba diving, **freediving, **surface-supplied diving, **saturation diving, and ** atmospheric suit diving People * Diver (surname) *Edward Divers (1837–1912), British chemist *"Diver", nickname of Tom Derrick (1914–1945), Australian Second World War recipient of the Victoria Cross Military *V-1 flying bomb, code named "diver" by the British World War II armed forces **Operation Diver, the British countermeasures against the German V-1 flying bomb campaign *AUM-N-4 Diver, a proposed U.S. Navy torpedo-carrying missile of the late 1940s. * Diver (United States Navy) Arts and entertainment * ''Diver'' (EP), a 2006 EP by A Wilhelm Scream * "Diver" (Nico Touches the Walls song), a 2011 song by Nico Touches the Walls * "Diver" (Kana-Boon song), a 2015 song by Kana-Boon * ''Divers'' (album), a 2015 album by Joanna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scuba Gas Planning
Scuba gas planning is the aspect of dive planning and of gas management which deals with the calculation or estimation of the amounts and mixtures of gases to be used for a planned dive. It may assume that the dive profile, including decompression, is known, but the process may be iterative, involving changes to the dive profile as a consequence of the gas requirement calculation, or changes to the gas mixtures chosen. Use of calculated reserves based on planned dive profile and estimated gas consumption rates rather than an arbitrary pressure is sometimes referred to as rock bottom gas management. The purpose of gas planning is to ensure that for all reasonably foreseeable contingencies, the divers of a team have sufficient breathing gas to safely return to a place where more breathing gas is available. In almost all cases this will be the surface. Gas planning includes the following aspects: * Choice of breathing gases * Choice of scuba configuration * Estimation of gas req ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrogen Narcosis
Narcosis while diving (also known as nitrogen narcosis, inert gas narcosis, raptures of the deep, Martini effect) is a reversible alteration in consciousness that occurs while diving at depth. It is caused by the anesthetic effect of certain gases at high pressure. The Greek word (narkōsis), "the act of making numb", is derived from (narkē), "numbness, torpor", a term used by Homer and Hippocrates. Narcosis produces a state similar to drunkenness (alcohol intoxication), or nitrous oxide inhalation. It can occur during shallow dives, but does not usually become noticeable at depths less than . Except for helium and probably neon, all gases that can be breathed have a narcotic effect, although widely varying in degree. The effect is consistently greater for gases with a higher lipid solubility, and although the mechanism of this phenomenon is still not fully clear, there is good evidence that the two properties are mechanistically related. As depth increases, the mental im ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
