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Freediving
Freediving, free-diving, free diving, breath-hold diving, or skin diving is a form of underwater diving that relies on breath-holding until resurfacing rather than the use of breathing apparatus such as scuba gear. Besides the limits of breath-hold, immersion in water and exposure to high ambient pressure also have physiological effects that limit the depths and duration possible in freediving. Examples of freediving activities are traditional fishing techniques, competitive and non-competitive freediving, competitive and non-competitive spearfishing and freediving photography, synchronised swimming, underwater football, underwater rugby, underwater hockey, underwater target shooting and snorkeling. There are also a range of "competitive apnea" disciplines; in which competitors attempt to attain great depths, times, or distances on a single breath. Historically, the term ''free diving'' was also used to refer to scuba diving, due to the freedom of movement compared with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freediving Blackout
Freediving blackout, breath-hold blackout or apnea blackout is a class of hypoxic blackout, a loss of consciousness caused by cerebral hypoxia towards the end of a breath-hold (freedive or dynamic apnea) dive, when the swimmer does not necessarily experience an urgent need to breathe and has no other obvious medical condition that might have caused it. It can be provoked by hyperventilating just before a dive, or as a consequence of the pressure reduction on ascent, or a combination of these. Victims are often established practitioners of breath-hold diving, are fit, strong swimmers and have not experienced problems before. Blackout may also be referred to as a syncope or fainting. Divers and swimmers who black out or grey out underwater during a dive will usually drown unless rescued and resuscitated within a short time. Freediving blackout has a high fatality rate, and mostly involves males younger than 40 years, but is generally avoidable. Risk cannot be quantified, but is c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Underwater Diving
Underwater diving, as a human activity, is the practice of descending below the water's surface to interact with the environment. It is also often referred to as diving, an ambiguous term with several possible meanings, depending on context. Immersion in water and exposure to high ambient pressure have physiological effects that limit the depths and duration possible in ambient pressure diving. Humans are not physiologically and anatomically well-adapted to the environmental conditions of diving, and various equipment has been developed to extend the depth and duration of human dives, and allow different types of work to be done. In ambient pressure diving, the diver is directly exposed to the pressure of the surrounding water. The ambient pressure diver may dive on breath-hold (freediving) or use breathing apparatus for scuba diving or surface-supplied diving, and the saturation diving technique reduces the risk of decompression sickness (DCS) after long-duration deep di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skandalopetra
diving () dates from ancient Greece, when it was used by sponge fishermen, and has been re-discovered in recent years as a freediving discipline. It was in this discipline that the first world record in freediving was registered, when the Greek sponge fisherman Stathis Chantzis dived to a depth of 83 m (272 ft) in July 1913. It consists of a variable ballast dive using a tied to a rope. A companion on a boat recovers the diver by pulling the rope up after the descent, and keeps a watch on the diver from the surface. Origins A skandalopetra dive known to contemporary divers is that of Stathis Chantzis, a Greek sponge fisherman who, on 14 July 1913, in the Karpathos port recovered the lost anchor of the Regina Margherita, a ship of the Italian Navy, at the depth of 83 m. That feat is considered the first depth record in apnea diving. The , or simply (), is a stone, usually of marble or granite, weighing between 8 and 14 kg, with rounded corners and hydrodynamic shape. It w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spearfishing
Spearfishing is a method of fishing that involves impaling the fish with a straight pointed object such as a spear, gig or harpoon. It has been deployed in artisanal fishing throughout the world for millennia. Early civilisations were familiar with the custom of spearing fish from rivers and streams using sharpened sticks. Modern spearfishing usually involves the use of underwater swimming gear and slingshot-like elastic powered spearguns or compressed gas powered pneumatic spearguns, which launch a tethered underwater projectile to strike the target fish. Specialised techniques and equipment have been developed for various types of aquatic environments and target fish. Spearfishing may be done using free-diving, snorkelling or scuba diving techniques, but spearfishing while using scuba equipment is illegal in some countries. The use of mechanically powered spearguns is also outlawed in some countries and jurisdictions such as New Zealand. Spearfishing uses no bait and is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snorkeling
Snorkeling ( British and Commonwealth English spelling: snorkelling) is the practice of swimming on or through a body of water while equipped with a diving mask, a shaped breathing tube called a snorkel, and usually swimfins. In cooler waters, a wetsuit may also be worn. Use of this equipment allows the snorkeler to observe underwater attractions for extended periods with relatively little effort and to breathe while face-down at the surface. Snorkeling is a popular recreational activity, particularly at tropical resort locations. It provides the opportunity to observe underwater life in a natural setting without the complicated equipment and training required for scuba diving. It appeals to all ages because of how little effort is involved and is the basis of the two surface disciplines of the underwater sport of finswimming. Snorkeling is also used by scuba divers when on the surface, in underwater sports such as underwater hockey and underwater rugby, and as part of wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Underwater Target Shooting
Underwater Target Shooting is an underwater sport/shooting sport that tests a competitors’ ability to accurately use a speargun via a set of individual and team events conducted in a swimming pool using freediving or Apnoea technique. The sport was developed in France during the early 1980s and is currently practiced mainly in Europe. It is known as ''Tir sur cible subaquatique'' in French and as ''Tiro al Blanco Subacuático'' in Spanish. Competitor admission requirements Competitors must be 18 years of age in order to participate in International events while National competitions in some countries such as France include age classifications for juniors and masters. The sport allows completion by both men and women. Individual events while conducted as mixed gender activities do have distinct men's and women's titles. Equipment Personal Each competitor is required to have the following equipment: diving mask, fins, snorkel, speargun, diving weighting system and an ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sponge Diving
Sponge diving is underwater diving to collect soft natural sponges for human use. Background Most sponges are too rough for general use due to their structural spicules composed of calcium carbonate or silica. But two genera, '' Hippospongia'' and '' Spongia'', have soft, entirely fibrous skeletons. These two genera are most commonly used by humans. It is unknown when exactly the sponge became an article of use. In Ancient Greek writings, Homer and Plato mentioned the sponge as an object used for bathing. Through trading, Europeans used soft sponges for many purposes including padding for helmets, portable drinking utensils and municipal water filters. Until the invention of synthetic sponges, they were used as cleaning tools, applicators for paints and ceramic glazes, and discreet contraceptives. However, by the mid-20th century, over-fishing had brought both the animals and the industry close to extinction. Many objects with sponge-like textures are now made of substances ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sponge
Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells. Sponges have unspecialized cells that can transform into other types and that often migrate between the main cell layers and the mesohyl in the process. Sponges do not have nervous, digestive or circulatory systems. Instead, most rely on maintaining a constant water flow through their bodies to obtain food and oxygen and to remove wastes. Sponges were first to branch off the evolutionary tree from the last common ancestor of all animals, making them the sister group of all other animals. Etymology The term ''sponge'' derives from the Ancient Greek word ( 'sponge'). Overview Sponges are similar to other animals in that they are multicel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pearl
A pearl is a hard, glistening object produced within the soft tissue (specifically the mantle) of a living shelled mollusk or another animal, such as fossil conulariids. Just like the shell of a mollusk, a pearl is composed of calcium carbonate (mainly aragonite or a mixture of aragonite and calcite) in minute crystalline form, which has deposited in concentric layers. The ideal pearl is perfectly round and smooth, but many other shapes, known as baroque pearls, can occur. The finest quality of natural pearls have been highly valued as gemstones and objects of beauty for many centuries. Because of this, ''pearl'' has become a metaphor for something rare, fine, admirable and valuable. The most valuable pearls occur spontaneously in the wild, but are extremely rare. These wild pearls are referred to as ''natural'' pearls. ''Cultured'' or ''farmed'' pearls from pearl oysters and freshwater mussels make up the majority of those currently sold. Imitation pearls are also wid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Salvage
Marine salvage is the process of recovering a ship and its cargo after a shipwreck or other maritime casualty. Salvage may encompass towing, re-floating a vessel, or effecting repairs to a ship. Today, protecting the coastal environment from spillage of oil or other contaminants is a high priority. Before the invention of radio, salvage services would be given to a stricken vessel by any ship that happened to be passing by. Nowadays, most salvage is carried out by specialist salvage firms with dedicated crew and equipment. The legal significance of salvage is that a successful salvor is entitled to a reward, which is a proportion of the total value of the ship and its cargo. The amount of the award is determined subsequently at a "hearing on the merits" by a maritime court in accordance with Articles 13 and 14 of the International Salvage Convention of 1989. The common law concept of salvage was established by the English Admiralty Court, and is defined as "a voluntary succes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agata Bogusz Wrakowe
Agata may refer to: * AGATA (organization), a Lithuanian non-profit performing rights organization Name * Agata (given name) * Agata (surname) Places *Agata Station, a train station in Ashikaga, Tochigi Prefecture, Japan Physics * AGATA (gamma-ray detector), Advance GAmma Tracking Array Miscellaneous * Agata (dog), a Colombian drug-detection dog * 7366 Agata, a main belt asteroid discovered in 1996 * Agata potato The Agata is a Dutch potato The potato is a starchy food, a tuber of the plant ''Solanum tuberosum'' and is a root vegetable native to the Americas. The plant is a perennial in the nightshade family Solanaceae. Wild potato species can ..., a potato variety * Histria Agata, a floating storage and offloading unit {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Military Campaign
A military campaign is large-scale long-duration significant military strategy plan incorporating a series of interrelated military operations or battles forming a distinct part of a larger conflict often called a war. The term derives from the plain of Campania, a place of annual wartime operations by the armies of the Roman Republic. Definition 1. A military campaign denotes the time during which a given military force conducts combat operations in a given area (often referred to as AO, area of operation). A military campaign may be executed by either a single Armed Service, or as a combined services campaign conducted by land, naval, air, cyber and space forces. 2. The purpose of a military campaign is to achieve a particular desired resolution of a military conflict as its strategic goal. This is constrained by resources, geography and/or season. A campaign is measured relative to the technology used by the belligerents to achieve goals, and while in the pre-industria ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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