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Underwater Orienteering
Underwater orienteering is an underwater sport that uses recreational open circuit scuba diving equipment and consists of a set of individual and team events conducted in both sheltered and open water testing the competitors' competency in underwater navigation. The competition is principally concerned with the effectiveness of navigation technique used by competitors to swim an underwater course following a route marked on a map prepared by the competition organisers, a compass and a counter meter to measure the distance covered. The sport was developed in the Soviet Union during the late 1950s and is played mainly in Europe. It is known as ''Orientation Sub'' in French and as '' La Orientación Subacuática'' in Spanish. Historically, the sport has also been known as ''Technical Disciplines''. Equipment Each competitor has the following recreational diving equipment: a diving mask, fins, a diving weighting system, an open circuit scuba set including diving cylinder filled with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
East Germany
East Germany, officially the German Democratic Republic (GDR; german: Deutsche Demokratische Republik, , DDR, ), was a country that existed from its creation on 7 October 1949 until its dissolution on 3 October 1990. In these years the state was a part of the Eastern Bloc in the Cold War. Commonly described as a communist state, it described itself as a socialist "workers' and peasants' state".Patrick Major, Jonathan Osmond, ''The Workers' and Peasants' State: Communism and Society in East Germany Under Ulbricht 1945–71'', Manchester University Press, 2002, Its territory was administered and occupied by Soviet forces following the end of World War II—the Soviet occupation zone of the Potsdam Agreement, bounded on the east by the Oder–Neisse line. The Soviet zone surrounded West Berlin but did not include it and West Berlin remained outside the jurisdiction of the GDR. Most scholars and academics describe the GDR as a totalitarian dictatorship. The GDR was establish ... [...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 navigation, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
