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History Of Underwater Diving
The history of underwater diving starts with freediving as a widespread means of hunting and gathering, both for food and other valuable resources such as pearls and coral, By classical Greek and Roman times commercial applications such as sponge diving and marine salvage were established, Military diving also has a long history, going back at least as far as the Peloponnesian War, with recreational and sporting applications being a recent development. Technological development in ambient pressure diving started with stone weights (skandalopetra) for fast descent. In the 16th and 17th centuries diving bells became functionally useful when a renewable supply of air could be provided to the diver at depth, and progressed to surface supplied diving helmets—in effect miniature diving bells covering the diver's head and supplied with compressed air by manually operated pumps—which were improved by attaching a waterproof suit to the helmet and in the early 19th century became ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alexander The Great Diving NOAA
Alexander is a male given name. The most prominent bearer of the name is Alexander the Great, the king of the Ancient Greek kingdom of Macedonia who created one of the largest empires in ancient history. Variants listed here are Aleksandar, Aleksander and Aleksandr. Related names and diminutives include Iskandar, Alec, Alek, Alex, Alexandre, Aleks, Aleksa and Sander; feminine forms include Alexandra, Alexandria, and Sasha. Etymology The name ''Alexander'' originates from the (; 'defending men' or 'protector of men'). It is a compound of the verb (; 'to ward off, avert, defend') and the noun (, genitive: , ; meaning 'man'). It is an example of the widespread motif of Greek names expressing "battle-prowess", in this case the ability to withstand or push back an enemy battle line. The earliest attested form of the name, is the Mycenaean Greek feminine anthroponym , , (/ Alexandra/), written in the Linear B syllabic script. Alaksandu, alternatively called ''Alakasandu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Diving Dress
Standard diving dress, also known as hard-hat or copper hat equipment, deep sea diving suit or heavy gear, is a type of diving suit that was formerly used for all relatively deep underwater work that required more than breath-hold duration, which included marine salvage, civil engineering, pearl shell diving and other commercial diving work, and similar naval diving applications. Standard diving dress has largely been superseded by lighter and more comfortable equipment. Standard diving dress consists of a diving helmet made from copper and brass or bronze, clamped over a watertight gasket to a waterproofed canvas suit, an air hose from a surface-supplied manually operated pump or low pressure breathing air compressor, a diving knife, and weights to counteract buoyancy, generally on the chest, back and shoes. Later models were equipped with a diver's telephone for voice communications with the surface. The term ''deep sea diving'' was used to distinguish diving with this equi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Diving Suit
An atmospheric diving suit (ADS) is a small one-person articulated submersible which resembles a suit of armour, with elaborate pressure joints to allow articulation while maintaining an internal pressure of one atmosphere. An ADS can enable diving at depths of up to for many hours by eliminating the majority of significant physiological dangers associated with deep diving. The occupant of an ADS does not need to decompress, and there is no need for special gas mixtures, so there is little danger of decompression sickness or nitrogen narcosis when the ADS is functioning properly. An ADS can permit less skilled swimmers to complete deep dives, albeit at the expense of dexterity. Atmospheric diving suits in current use include the Newtsuit, Exosuit, Hardsuit and the WASP, all of which are self-contained hard suits that incorporate propulsion units. The Hardsuit is constructed from cast aluminum (forged aluminum in a version constructed for the US Navy for submarine rescue); the u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decompression Sickness
Decompression sickness (abbreviated DCS; also called divers' disease, the bends, aerobullosis, and caisson disease) is a medical condition caused by dissolved gases emerging from solution as bubbles inside the body tissues during decompression. DCS most commonly occurs during or soon after a decompression ascent from underwater diving, but can also result from other causes of depressurisation, such as emerging from a caisson, decompression from saturation, flying in an unpressurised aircraft at high altitude, and extravehicular activity from spacecraft. DCS and arterial gas embolism are collectively referred to as decompression illness. Since bubbles can form in or migrate to any part of the body, DCS can produce many symptoms, and its effects may vary from joint pain and rashes to paralysis and death. DCS often causes air bubbles to settle in major joints like knees or elbows, causing individuals to bend over in excruciating pain, hence its common name, the bends. Individu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saturation Diving
Saturation diving is diving for periods long enough to bring all tissues into equilibrium with the partial pressures of the inert components of the breathing gas used. It is a diving mode that reduces the number of decompressions divers working at great depths must undergo by only decompressing divers once at the end of the diving operation, which may last days to weeks, having them remain under pressure for the whole period. A diver breathing pressurized gas accumulates dissolved inert gas used in the breathing mixture to dilute the oxygen to a non-toxic level in his or her tissues, which can cause decompression sickness ("the bends") if permitted to come out of solution within the body tissues; hence, returning to the surface safely requires lengthy decompression so that the inert gases can be eliminated via the lungs. Once the dissolved gases in a diver's tissues reach the saturation point, however, decompression time does not increase with further exposure, as no more inert g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heliox
Heliox is a breathing gas mixture of helium (He) and oxygen (O2). It is used as a medical treatment for patients with difficulty breathing because mixture generates less resistance than atmospheric air when passing through the airways of the lungs, and thus requires less effort by a patient to breathe in and out of the lungs. It is also used as a breathing gas diluent for deep ambient pressure diving as it is not narcotic at high pressure, and for its low work of breathing. Heliox has been used medically since the 1930s, and although the medical community adopted it initially to alleviate symptoms of upper airway obstruction, its range of medical uses has since expanded greatly, mostly because of the low density of the gas. Heliox is also used in saturation diving and sometimes during the deep phase of technical dives. Medical uses In medicine heliox may refer to a mixture of 21% O2 (the same as air) and 79% He, although other combinations are available (70/30 and 60/40). Hel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diving Helmet
A diving helmet is a rigid head enclosure with a breathing gas supply used in underwater diving. They are worn mainly by professional divers engaged in surface-supplied diving, though some models can be used with scuba equipment. The upper part of the helmet, known colloquially as the ''hat'' or ''bonnet'', may be sealed directly to the diver using a ''neck dam'', connected to a diving suit by a lower part, known as a ''breastplate'', or ''corselet'', depending on regional language preferences. or simply rest on the diver's shoulders, with an open bottom, for shallow water use. The helmet isolates the diver's head from the water, allows the diver to see clearly underwater, provides the diver with breathing gas, protects the diver's head when doing heavy or dangerous work, and usually provides voice communications with the surface (and possibly other divers). If a helmeted diver becomes unconscious but is still breathing, most helmets will remain in place and continue to deliver b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Technical Diving
Technical diving (also referred to as tec diving or tech diving) is scuba diving that exceeds the agency-specified limits of recreational diving Recreational diving or sport diving is diving for the purpose of leisure and enjoyment, usually when using scuba equipment. The term "recreational diving" may also be used in contradistinction to "technical diving", a more demanding aspect of ... for non-Professional diver, professional purposes. Technical diving may expose the diver to hazards beyond those normally associated with recreational diving, and to a greater risk of serious injury or death. The risk may be reduced by appropriate skills, knowledge and experience, and by using suitable equipment and procedures. The skills may be developed through appropriate specialised training and experience. The equipment often involves breathing gases other than air or standard nitrox mixtures, and multiple gas sources. The popularisation of the term ''technical diving'' has been credi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Media Diving
Media diving is underwater diving in support of the media industries, including the practice of underwater photography and underwater cinematography outside of normal recreational interests. Media diving is often carried out in support of television documentaries, such as the BBC series Planet Earth or movies, with feature films such as Titanic and The Perfect Storm featuring underwater photography or footage. Media divers are normally highly skilled camera operators who use diving as a method to reach their workplace, although some underwater photographers start as recreational divers and move on to make a living from their hobby. Equipment in this field is varied with scuba and surface supplied equipment used, depending on requirements, but rebreathers are often used for wildlife related work as they are normally quiet, release few or no bubbles and allow the diver a lengthy bottom time with a reduced risk of frightening off the subject. Applications and scope of work Media d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Public Safety Diving
Public safety diving is underwater diving conducted as part of law enforcement and search and rescue. Public safety divers differ from recreational, scientific and commercial divers who can generally plan the date, time, and location of a dive, and dive only if the conditions are conducive to the task. Public safety divers respond to emergencies 24 hours a day, 7 days a week, and may be required to dive in the middle of the night, during inclement weather, in zero visibility "black water," or in waters polluted by chemicals and biohazards. Specialized skills In addition to basic diving skills training, public safety divers require specialized training for recognizing hazards, conducting risk assessments, search procedures, diving in zero visibility, using full-face masks with communication systems, and recovering evidence that is admissible in court. Some of the water they are required to dive in is contaminated, and they may be required to wear vulcanized drysuits, with d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scientific Diving
Scientific diving is the use of underwater diving techniques by scientists to perform work underwater in the direct pursuit of scientific knowledge. The legal definition of scientific diving varies by jurisdiction. Scientific divers are normally qualified scientists first and divers second, who use diving equipment and techniques as their way to get to the location of their fieldwork. The direct observation and manipulation of marine habitats afforded to scuba-equipped scientists have transformed the marine sciences generally, and marine biology and marine chemistry in particular. Underwater archeology and geology are other examples of sciences pursued underwater. Some scientific diving is carried out by universities in support of undergraduate or postgraduate research programs, and government bodies such as the United States Environmental Protection Agency and the UK Environment Agency carry out scientific diving to recover samples of water, marine organisms and sea, lake or riverb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frogman
A frogman is someone who is trained in scuba diving or swimming underwater in a tactical capacity that includes military, and in some European countries, police work. Such personnel are also known by the more formal names of combat diver, combatant diver, or combat swimmer. The word ''frogman'' first arose in the stage name ''The Fearless Frogman'' of Paul Boyton in the 1870s and later was claimed by John Spence, an enlisted member of the U.S. Navy and member of the OSS Maritime Unit, to have been applied to him while he was training in a green waterproof suit. The term ''frogman'' is occasionally used to refer to a civilian scuba diver. Some sport diving clubs include the word ''Frogmen'' in their names. The preferred term by scuba users is ''diver'', but the ''frogman'' epithet persists in informal usage by non-divers, especially in the media and often referring to professional scuba divers, such as in a police diving role. In the U.S. military and intelligence community ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
