|
Frogman
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] |
John Spence (frogman)
John Pitts Spence (June 14, 1918 – October 29, 2013) was an American diver for the United States Navy and World War II veteran who is widely credited as the country's first combat frogman. Spence was the first enlisted man to be recruited into a clandestine group, operated by General William J. Donovan, William "Wild Bill" Donovan of the Office of Strategic Services (OSS), which would become known as the frogmen. The group was a predecessor of the present-day United States Navy SEALs. The origin of the term "frogman" can be traced directly to John Spence. In an interview with maritime historian Erick Simmel, Spence explained that frogman first came into use while he was training in a green, waterproof suit. Spence recalled, "Someone saw me surfacing one day and yelled out, 'Hey, frogman!' The name stuck for all of us." Spence and the other men trained in underwater close combat techniques, demolition and stealth in order to destroy underwater emplacements and enemy ships during W ... [...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] |
Clearance Diver
A clearance diver was originally a specialist naval underwater diving, diver who used explosives underwater to remove obstructions to make harbours and shipping channels safe to navigate, but the term "clearance diver" was later used to include other naval underwater work. Units of clearance divers were first formed during and after World War II to clear ports and harbours in the Mediterranean and Northern Europe of unexploded ordnance and shipwrecks and booby traps laid by the Kriegsmarine, Germans. History Clearance Diving takes its name from the operations carried out towards the end and after the Second World War to clear the ports and harbours of the Mediterranean Sea, Mediterranean and Northern Europe of unexploded ordnance and booby traps laid by the Germans.This work was undertaken by RN Rendering Mines Safe (RMS) and Bomb Disposal Units and later by Port Clearance Parties or ‘P’ Parties, two of which (Naval Parties 1571 and 1572) went into action soon after Norman ... [...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] |
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] |
Limpet Mine
A limpet mine is a type of naval mine attached to a target by magnets. It is so named because of its superficial similarity to the shape of the limpet, a type of sea snail that clings tightly to rocks or other hard surfaces. A swimmer or diver may attach the mine, which is usually designed with hollow compartments to give the mine just slight negative buoyancy, making it easier to handle underwater. Types of fuses Usually limpet mines are set off by a time fuse. They may also have an anti-handling device, making the mine explode if removed from the hull by enemy divers or by explosions. Sometimes limpet mines have been fitted with a small turbine which would detonate the mine after the ship had sailed a certain distance, so that it was likely to sink in navigable channels (to make access difficult for other ships) or deep water (out of reach of easy salvage) and making determination of the cause of the sinking more difficult. Development In December 1938, a new unit was c ... [...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] |
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] |
Amphibious Assault
Amphibious warfare is a type of offensive military operation that today uses naval ships to project ground and air power onto a hostile or potentially hostile shore at a designated landing beach. Through history the operations were conducted using ship's boats as the primary method of delivering troops to shore. Since the Gallipoli Campaign, specialised watercraft were increasingly designed for landing troops, material and vehicles, including by landing craft and for insertion of commandos, by fast patrol boats, zodiacs (rigid inflatable boats) and from mini-submersibles. The term ''amphibious'' first emerged in the United Kingdom and the United States during the 1930s with introduction of vehicles such as Vickers-Carden-Loyd Light Amphibious Tank or the Landing Vehicle Tracked.The first LVT prototypes were named ''Alligator'' and ''Crocodile'', though neither species is actual amphibian Amphibious warfare includes operations defined by their type, purpose, scale and me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Submarine Communications Cable
A submarine communications cable is a cable laid on the seabed between land-based stations to carry telecommunication signals across stretches of ocean and sea. The first submarine communications cables were laid beginning in the 1850s and carried telegraphy traffic, establishing the first instant telecommunications links between continents, such as the first transatlantic telegraph cable which became operational on 16 August 1858. Submarine cables first connected all the world's continents (except Antarctica) when Java was connected to Darwin, Northern Territory, Australia, in 1871 in anticipation of the completion of the Australian Overland Telegraph Line in 1872 connecting to Adelaide, South Australia and thence to the rest of Australia. Subsequent generations of cables carried telephone traffic, then data transmission, data communications traffic. These early cables used copper wires in their cores, but modern cables use optical fiber technology to carry digital data, whic ... [...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] |
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] |
