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Buoy
A buoy (; ) is a buoyancy, floating device that can have many purposes. It can be anchored (stationary) or allowed to drift with ocean currents. History The ultimate origin of buoys is unknown, but by 1295 a seaman's manual referred to navigation buoys in the Guadalquivir River in Spain. To the north there are early medieval mentions of the French / Belgian River Meuse, Maas being buoyed. Such early buoys were probably just timber beams or rafts, but in 1358 there is a record of a barrel buoy in the Dutch Maasmond (also known as the Maas Sluis or Maasgat). The simple barrel was difficult to secure to the seabed, and so a conical ''tonne'' was developed. They had a solid plug at the narrow end through which a mooring ring could be attached. By 1790 the older conical tonne was being replaced by a ''nun'' buoy. This had the same conical section below the waterline as the tonne buoy, but at the waterline a barrel shape was used to allow a truncated cone to be above the water. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buoyancy
Buoyancy (), or upthrust, is the force exerted by a fluid opposing the weight of a partially or fully immersed object (which may be also be a parcel of fluid). In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus, the pressure at the bottom of a column of fluid is greater than at the top of the column. Similarly, the pressure at the bottom of an object submerged in a fluid is greater than at the top of the object. The pressure difference results in a net upward force on the object. The magnitude of the force is proportional to the pressure difference, and (as explained by Archimedes' principle) is equivalent to the weight of the fluid that would otherwise occupy the submerged volume of the object, i.e. the Displacement (fluid), displaced fluid. For this reason, an object with average density greater than the surrounding fluid tends to sink because its weight is greater than the weight of the fluid it displaces. If the objec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Underwater Orienteering
Underwater orienteering, also known as scuba 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emergency Wreck Buoy
An Emergency wreck buoy is used to warn of a new wreck which has not yet been listed in maritime documents. The buoy is expected to be deployed for the first 24-72 hours after the wreck occurs. After that time more permanent buoyage (such as isolated danger marks or cardinal marks) should be deployed and charts updated. The buoy is designed to "provide a clear and unambiguous" mark of a new and uncharted danger. The buoy is painted with 4, 6 or 8 vertical stripes of alternate yellow and blue. In addition it may have the word "WRECK" painted on it. Optionally it may carry a vertical (St. George's) cross painted yellow. The light flashes alternate yellow and blue for one second each with a half second gap between. No other navigation mark uses blue. The International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA) defined the buoy in response to the sinking of the and the subsequent collisions with the wreck by the Dutch vessel ''Nicola'' and Tur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Mark
A sea mark, also seamark and navigation mark, is a form of aid to navigation and pilotage that identifies the approximate position of a maritime channel, hazard, or administrative area to allow boats, ships, and seaplanes to navigate safely. There are three types of sea mark: beacons fixed to the seabed or on shore, towers (sometimes rock cairns) built on the shore or on a submerged rock/object (especially in calmer waters), and buoys (consisting of a floating object that is usually anchored to a specific location on the bottom of the sea or to a submerged object). Sea marks are used to indicate channels, dangerous rocks or shoals, mooring positions, areas of speed limits, traffic separation schemes, submerged shipwrecks, and for a variety of other navigational purposes. Some are only intended to be visible in daylight ('' daymarks''), others have some combination of lights, reflectors, fog bells, foghorns, whistles and radar reflectors to make them usable at night and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Julius Pintsch
Carl Friedrich Julius Pintsch (6 January 1815 – 20 January 1884) was a German tinsmith, manufacturer and inventor who is primarily known for the invention of Pintsch gas. The gas, distilled from naphtha or other petroleum products, was widely used in railway transport and marine navigation applications from its invention in 1851 until the 1930s. Life Born in Berlin, Pintsch completed an apprenticeship as a tinsmith in 1833 and, after his journeyman years, took up a position at a local lamp factory. Having obtained his ''Meister'' certificate, he established his own small workshop near the municipal gasworks at Frankfurter Bahnhof in Berlin-Friedrichshain, in 1843. While the City of Berlin continuously enlarged its gas network in order to supply the growing population, Pintsch received numerous repair orders from the public GASAG utility company. He achieved major success in 1847 with the development of a reliable gas meter that was used by the city administration and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Navigational Aid
A navigational aid (NAVAID), also known as aid to navigation (ATON), is any sort of signal, markers or guidance equipment which aids the traveler in navigation, usually nautical or aviation travel. Common types of such aids include lighthouses, buoys, fog signals, and day beacons. Definition According to the glossary of terms in the United States Coast Guard Light list, an ''aid to navigation'' (ATON) is any device external to a vessel or aircraft specifically intended to assist navigators in determining their position or safe course, or to warn them of dangers or obstructions to navigation. Lateral marks Lateral marks indicate the edge of the channel. The standards are defined by the International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA). Approaching harbour port a vessel leaves port hand marks to port (left) and starboard hand marks to starboard (right). Port hand marks are cylindrical, starboard marks are conical. If the mark is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boat
A boat is a watercraft of a large range of types and sizes, but generally smaller than a ship, which is distinguished by its larger size or capacity, its shape, or its ability to carry boats. Small boats are typically used on inland waterways such as rivers and lakes, or in protected coastal areas. However, some boats (such as whaleboats) were intended for offshore use. In modern Navy, naval terms, a boat is a vessel small enough to be carried aboard a ship. Boats vary in proportion and construction methods with their intended purpose, available materials, or local traditions. Canoes have been used since prehistoric times and remain in use throughout the world for transportation, fishing, and sport. Fishing boats vary widely in style partly to match local conditions. Pleasure boat, Pleasure craft used in boating, recreational boating include ski boats, Pontoon (boat), pontoon boats, and sailboats. House boats may be used for vacationing or long-term residence. Lighter (barge), L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lightvessel
A lightvessel, or lightship, is a ship that acts as a lighthouse. It is used in waters that are too deep or otherwise unsuitable for lighthouse construction. Although some records exist of fire beacons being placed on ships in Roman times, the first modern lightship was located off the Nore sandbank at the mouth of the River Thames in London, England, by its inventor Robert Hamblin in 1734. Lightships have since been rendered obsolete by advancing lighthouse construction techniques, and by LANBY, large automated navigation buoys. Construction The most important element of lightship design is a tall Mast (sailing), mast upon which to mount the light. Initially, these lights consisted of Oil lamp, oil lamps that were run up the mast and could be lowered for servicing, while later vessels carried fixed lamps which were serviced in place. As they became available, Fresnel lenses were used, and many vessels housed them in smaller versions of lighthouse lanterns. Some lightships ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lanby Buoy
LANBY, a contraction of Large Automatic Navigation BuoY, was a type of floating navigational aid designed to replace lightships. Now obsolete, they were originally made in the USA by General Dynamics and adapted by Hawker Siddeley Dynamics for use in British waters in the early 1970s. They consisted of a circular hull with a raised central structure containing a 360° light and foghorn, and sometimes also a radio beacon. They were monitored from onshore and designed to run for extended periods without repair. Their running costs were estimated to be as low as 10% of those of lightships. Equipment UK models followed the General Dynamics design: Power was supplied by three diesel alternators of 230 V, individually rated at 5 kW continuous output. These were each run in a 72-hour operational cycle of 24 hours under power, followed by 48 at rest. Maintenance and refuelling was at six-month intervals. A static rectifier provided continuous power at 28 V DC, cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fairway Buoy
Examples of Safe Water Marks A safe water mark, as defined by the International Association of Lighthouse Authorities, is a sea mark used in maritime pilotage to indicate the end of a channel. They usually imply that open, deep and safe water lies ahead. They are also used to indicate the start and end of a buoyed section of a continuous narrow channel; and a series of them may mark a safe route through shallow areas. It is therefore important to consult appropriate charts to determine their meaning in each location. They are also known as fairway buoys and clear water buoys. They are recognisable by their red-and-white vertical stripes and commonly bear a top sign in shape of a red ball. They either flash Morse code "A" (di-dah), or one long flash, occulting (more light than dark) or isophase (equal light and dark) every 10 seconds (L Fl 10s).Haire, Penny.''Yachtmaster''. Royal Yachting Association, 2009, p. 61. In the United States, safe water marks are printed with the initi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anchor
An anchor is a device, normally made of metal, used to secure a vessel to the bed of a body of water to prevent the craft from drifting due to wind or current. The word derives from Latin ', which itself comes from the Greek (). Anchors can either be temporary or permanent. Permanent anchors are used in the creation of a mooring, and are rarely moved; a specialist service is normally needed to move or maintain them. Vessels carry one or more temporary anchors, which may be of different designs and weights. A sea anchor is a drag device, not in contact with the seabed, used to minimize drift of a vessel relative to the water. A drogue is a drag device used to slow or help steer a vessel running before a storm in a following or overtaking sea, or when crossing a bar in a breaking sea. Anchoring Anchors achieve holding power either by "hooking" into the seabed, or weight, or a combination of the two. The weight of the anchor chain can be more than that of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
