|
Frogmen
A frogman is someone who is trained in scuba diving or swimming underwater. The term often applies more to professional rather than recreational divers, especially those working 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, such as in a police diving role. In the United Kingdom, police divers have often been called "police frogmen". Some countries' tactical diver organizations include a translation of the word ''frogman'' in their official names, e.g., Denmark ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scuba Diving
Scuba diving is a Diving mode, mode of underwater diving whereby divers use Scuba set, breathing equipment that is completely independent of a surface breathing gas supply, and therefore has a limited but variable endurance. The word ''scuba'' is an Acronym#Normal case and acronyms, acronym for "Self-Contained Underwater Breathing Apparatus" and was coined by Christian J. Lambertsen in a patent submitted in 1952. Scuba divers carry their own source of breathing gas, affording them greater independence and movement than surface-supplied divers, and more time underwater than freedivers. Although the use of compressed air is common, other gas blends are also used. Open-circuit scuba systems discharge the breathing gas into the environment as it is exhaled and consist of one or more diving cylinders containing breathing gas at high pressure which is supplied to the diver at ambient pressure through a diving regulator. They may include additional cylinders for range extension, de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OSS Maritime Unit
The Maritime Unit (MU) was a branch of the Office of Strategic Services that enabled maritime warfare for the allies during World War II. MU's mission was to "infiltrate agents and supply resistance groups by sea, conduct maritime sabotage, and to develop specialized maritime surface and subsurface equipment and devices." MU developed specialized boats, equipment, and explosives, fashioned underwater breathing gear, waterproof watches and compasses, an inflatable motorized surfboard, and "a two-man kayak that proved so promising that 275 were ordered by the British." MU was originally established as a division of the Special Operations Branch of the OSS but was granted Branch status on June 10, 1942. The Frogmen of the MU are considered pioneers of amphibious, maritime, and underwater warfare. While it was a civilian agency, the United States Navy SEALS state clearly that the OSS Maritime Unit is one of their direct preceding organizations. MU planned and carried out the amphi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bomb Disposal
Bomb disposal is an explosives engineering profession using the process by which hazardous explosive devices are disabled or otherwise rendered safe. ''Bomb disposal'' is an all-encompassing term to describe the separate, but interrelated functions in the military fields of explosive ordnance disposal (EOD) and improvised explosive device disposal (IEDD), and the Public security, public safety roles of public safety bomb disposal (PSBD) and the bomb squad. History The first professional civilian bomb squad was established by Colonel Sir Vivian Dering Majendie a Major (rank), Major at the time in the Royal Artillery, Majendie investigated an explosion on 2 October 1874 in the Regent's Canal, when the barge 'Tilbury', carrying six barrels of petroleum and five tons of gunpowder, blew up, killing the crew and destroying Macclesfield Bridge and cages at nearby London Zoo. In 1875, he framed the Explosives Act 1875, Explosives Act, the first modern legislation for explosives contro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
US Navy 050505-N-3093M-001 A Member Of SEAL Delivery Vehicle Team Two (SDVT-2) Climbs Aboard One Of The Team's SEAL Delivery Vehicles (SDV) Before Launching From The Back Of The Los Angeles-class Attack Submarine USS Philadelph
US or Us most often refers to: * ''Us'' (pronoun), the objective case of the English first-person plural pronoun ''we'' * US, an abbreviation for the United States US, U.S., Us, us, or u.s. may also refer to: Arts and entertainment Albums * ''Us'' (Brother Ali album) or the title song, 2009 * ''Us'' (Empress Of album), 2018 * ''Us'' (Mull Historical Society album), 2003 * ''Us'' (Peter Gabriel album), 1992 * ''Us'' (EP), by Moon Jong-up, 2021 * ''Us'', by Maceo Parker, 1974 * ''Us'', mini-album by Peakboy, 2019 Songs * "Us" (James Bay song), 2018 * "Us" (Jennifer Lopez song), 2018 * "Us" (Regina Spektor song), 2004 * "Us" (Gracie Abrams song), 2024 * "Us", by Azealia Banks from '' Fantasea'', 2012 * "Us", by Celine Dion from ''Let's Talk About Love'', 1997 * "Us", by Gucci Mane from '' Delusions of Grandeur'', 2019 * "Us", by Spoon from '' Hot Thoughts'', 2017 Other media * US Festival, two 1980s California music festivals organized by Steve Wozniak * ''Us'' (1991 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Navy Frogman
British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories and Crown Dependencies. * British national identity, the characteristics of British people and culture * British English, the English language as spoken and written in United Kingdom of Great Britain and Northern Ireland and, more broadly, throughout the British Isles * Celtic Britons, an ancient ethno-linguistic group * Brittonic languages, a branch of the Insular Celtic language family (formerly called British) ** Common Brittonic, an ancient language Other uses *People or things associated with: ** Great Britain, an island ** British Isles, an island group ** United Kingdom, a sovereign state ** British Empire, a historical global colonial empire ** Kingdom of Great Britain (1707–1800) ** United Kingdom of Great Britain and Ireland (1801–1922) * British Raj, colonial India under the British Empire * British Hong Kong, colonial Ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waterproof
Waterproofing is the process of making an object, person or structure waterproof or water-resistant so that it remains relatively unaffected by water or resists the ingress of water under specified conditions. Such items may be used in wet environments or underwater to specified depths. ''Water-resistant'' and ''waterproof'' often refer to resistance to penetration of water in its liquid state and possibly under pressure, whereas '' damp proof'' refers to resistance to humidity or dampness. Permeation of water vapour through a material or structure is reported as a moisture vapor transmission rate (MVTR). The hulls of boats and ships were once waterproofed by applying tar or pitch. Modern items may be waterproofed by applying water-repellent coatings or by sealing seams with gaskets or o-rings. Waterproofing is used in reference to building structures (such as basements, decks, or wet areas), watercraft, canvas, clothing ( raincoats or waders), electronic devices and pape ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immersion Suit
An immersion suit, also known as a survival suit, is a type of waterproof dry suit intended to protect the wearer from hypothermia if immersed in cold water or otherwise exposed after abandoning a vessel, especially in the open ocean. Immersion suits usually have integral footwear, and a hood, and either built-in gloves or watertight wrist seals. Suits manufactured by several manufacturers also include an inflatable pillow which is permanently attached high on the back, or an inflatable tube that is attached with zippers at two points on the chest, each side of the main zipper, and circles the back. Immersion suits are of two types: Work suits are worn for long periods in high risk environments, and survival suits are worn during emergencies. When inflated, both of these devices provide enhanced stability to the wearer, which, if conscious, allows them to keep the head above water, and to keep wind and seas from striking the face. The inflation tube is routed from the inflatabl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrophone
A hydrophone () is a microphone designed for underwater use, for recording or listening to underwater sound. Most hydrophones contains a piezoelectric transducer that generates an electric potential when subjected to a pressure change, such as a sound wave. A hydrophone can also detect airborne sounds but is insensitive of them because it is designed to match the acoustic impedance of water, a denser fluid than air. Sound travels 4.3 times faster in water than in air, and a sound wave in water exerts a pressure 60 times more than what is exerted by a wave of the same amplitude in air. Similarly, a standard microphone can be buried in the ground, or immersed in water if it is put in a waterproof container but will give poor performance because of the similarly-bad acoustic impedance match. History The first hydrophones consisted of a tube with a thin membrane covering the submerged end and the observer's ear of the equipment. The design of effective hydrophones must take into a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open-circuit Scuba
A scuba set, originally just scuba, is any breathing apparatus that is entirely carried by an underwater diving, underwater diver and provides the diver with breathing gas at the ambient pressure. ''Scuba'' is an anacronym for self-contained underwater breathing apparatus. Although strictly speaking the scuba set is only the diving equipment that is required for providing breathing gas to the diver, general usage includes the harness or rigging by which it is carried and those accessories which are integral parts of the harness and breathing apparatus assembly, such as a jacket or wing style Buoyancy compensator (diving), buoyancy compensator and instruments mounted in a combined housing with the pressure gauge. In the looser sense, scuba set has been used to refer to all the diving equipment used by the scuba diver, though this would more commonly and accurately be termed scuba equipment or scuba gear. Scuba is overwhelmingly the most common underwater breathing system used by r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rebreather
A rebreather is a breathing apparatus that absorbs the carbon dioxide of a user's exhaled breath to permit the rebreathing (recycling) of the substantial 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, while also eliminating the bubbles otherwise produced by an open circuit system. The latter advantage over other systems is useful for covert military operations by frogmen, as well as for undisturbed observation of underwater wildlife. A rebreather is generally understood to be a portable apparatus 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 supp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eavesdropping
Eavesdropping is the act of secretly or stealthily listening to the private conversation or communications of others without their consent in order to gather information. Etymology The verb ''eavesdrop'' is a back-formation from the noun ''eavesdropper'' ("a person who eavesdrops"), which was formed from the related noun ''eavesdrop'' ("the dripping of water from the eaves of a house; the ground on which such water falls"). An eavesdropper was someone who would hang from the eave of a building so as to hear what is said within. The PBS documentaries ''Inside the Court of Henry VIII'' (April 8, 2015) and ''Secrets of Henry VIII’s Palace'' (June 30, 2013) include segments that display and discuss "eavedrops", carved wooden figures Henry VIII had built into the eaves (overhanging edges of the beams in the ceiling) of Hampton Court to discourage unwanted gossip or dissension from the King's wishes and rule, to foment paranoia and fear, and demonstrate that everything said there wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sonar
Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances ( ranging), communicate with or detect objects on or under the surface of the water, such as other vessels. "Sonar" can refer to one of two types of technology: ''passive'' sonar means listening for the sound made by vessels; ''active'' sonar means emitting pulses of sounds and listening for echoes. Sonar may be used as a means of acoustic location and of measurement of the echo characteristics of "targets" in the water. Acoustic location in air was used before the introduction of radar. Sonar may also be used for robot navigation, and sodar (an upward-looking in-air sonar) is used for atmospheric investigations. The term ''sonar'' is also used for the equipment used to generate and receive the sound. The acoustic frequencies used in sonar systems vary from very low ( infrasonic) to e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
