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Decompression Buoy
A surface marker buoy, SMB, dive float or simply a blob is a buoy used by scuba divers, at the end of a line from the diver, intended to indicate the diver's position to people at the surface while the diver is underwater. Two kinds are used; one (SMB) is towed for the whole dive, and indicates the position of the dive group throughout the dive, and the other, a delayed surface marker buoy, DSMB or decompression buoy, is deployed towards the end of the dive as a signal to the surface that the divers have started to ascend, and where they are going to surface. Both types can also function as a depth reference for controlling speed of ascent and accurately maintaining depth at decompression stops. Surface marker buoys are also used by freedivers in open water, to indicate the approximate position of the diver when submerged. They may also be used to support a catch bag or fish stringer by underwater hunters and collectors. A DSMB is considered by recreational scuba divers and serv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buoy
A buoy () is a floating device that can have many purposes. It can be anchored (stationary) or allowed to drift with ocean currents. Types Navigational buoys * Race course marker buoys are used for buoy racing, the most prevalent form of yacht racing and power boat racing. They delimit the course and must be passed to a specified side. They are also used in underwater orienteering competitions. * Emergency wreck buoys provide a clear and unambiguous means of temporarily marking new wrecks, typically for the first 24–72 hours. They are coloured in an equal number of blue and yellow vertical stripes and fitted with an alternating blue and yellow flashing light. They were implemented following collisions in the Dover Strait in 2002 when vessels struck the new wreck of the . * Ice marking buoys mark holes in frozen lakes and rivers so snowmobiles do not drive over the holes. * Large Navigational Buoys (LNB, or Lanby buoys) are automatic buoys over 10 m high equipped wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buoyancy Compensator (diving)
A buoyancy compensator (BC), also called a buoyancy control device (BCD), stabilizer, stabilisor, stab jacket, wing or adjustable buoyancy life jacket (ABLJ), depending on design, is a type of diving equipment which is worn by divers to establish neutral buoyancy underwater and positive buoyancy at the surface, when needed. The buoyancy is usually controlled by adjusting the volume of gas in an inflatable bladder, which is filled with ambient pressure gas from the diver's primary breathing gas cylinder via a low-pressure hose from the regulator first stage, directly from a small cylinder dedicated to this purpose, or from the diver's mouth through the oral inflation valve. Ambient pressure bladder buoyancy compensators can be broadly classified as having the buoyancy primarily in front, surrounding the torso, or behind the diver. This affects the ergonomics, and to a lesser degree, the safety of the unit. They can also be broadly classified as having the buoyancy bladder as an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bolt Snap
A bolt snap is a type of snap hook with a manually operated bolt action slide gate of medium security used to clip a light load to a ring, eye, loop or bight to temporarily secure or suspend an object. They are used for a wide variety of applications including dog leads and for clipping scuba equipment to the diving harness. A similar but more secure device used to attach sails to a stay is known as a piston hank. It differs from a snap shackle in that the load is not carried by the gate. The bolt snap must be actively operated by the user to clip or unclip, and is not easily snagged or unintentionally clipped or unclipped by pressing or bumping against the surroundings. The most common type has a single snap hook at one end and a swivel ring at the other, but double ended bolt snaps and single ended snaps with a swivel shackle are also available. There are a few variations on the style of the hook, gate opening and swivel style. The characteristic element of the bolt snap is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slate (writing)
A slate is a thin piece of hard flat material, historically slate, slate stone, which is used as a medium for writing. Composition The writing slate consisted of a piece of slate, typically either 4x6 inches or 7x10 inches, encased in a wooden frame. A slate pencil was used to write on the slate board. It was made from a softer and lighter coloured stone such as shale or chalk. Usually, a piece of cloth or slate sponge was used to clean it and this was sometimes attached with a string to the bottom of the writing slate. History The exact origins of the writing slate remain unclear. References to its use can be found in the fourteenth century and evidence suggests that it was used in the sixteenth and seventeenth centuries. The central time period for the writing slate, however, "appears to begin in the later eighteenth century, when developments in sea and land transport permitted the gradual expansion of slate quarrying in Wales and the growth of a substantial slate wor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyalume Stick
A glow stick, also known as a light stick, chem light, light wand, light rod, and rave light, is a self-contained, short-term light-source. It consists of a translucent plastic tube containing isolated substances that, when combined, make light through chemiluminescence. The light cannot be turned off and can be used only once. The used tube is then thrown away. Glow sticks are often used for recreation, such as for events, camping, outdoor exploration, and concerts. Glow sticks are also used for light in military and emergency services applications. Industrial uses include marine, transportation, and mining. History Bis(2,4,5-trichlorophenyl-6-carbopentoxyphenyl)oxalate, trademarked "Cyalume", was invented in 1971 by Michael M. Rauhut, of American Cyanamid, based on work by Edwin A. Chandross of Bell Labs. Other early work on chemiluminescence was carried out at the same time, by researchers under Herbert Richter at China Lake Naval Weapons Center. Several US patents for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strobe Light
A strobe light or stroboscopic lamp, commonly called a strobe, is a device used to produce regular flashes of light. It is one of a number of devices that can be used as a stroboscope. The word originated from the Ancient Greek ('), meaning "act of whirling". A typical commercial strobe light has a flash energy in the region of 10 to 150 joules, and discharge times as short as a few milliseconds, often resulting in a flash power of several kilowatts. Larger strobe lights can be used in “continuous” mode, producing extremely intense illumination. The light source is commonly a xenon flash lamp, or ''flashtube'', which has a complex spectrum and a color temperature of approximately 5,600 kelvins. To obtain colored light, colored gels may be used. Scientific explanation of flashtubes Strobe lights usually use flashtubes with energy supplied from a capacitor, an energy storage device much like a battery, but capable of charging and releasing energy much faster. In a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reel With DSMB P9027417 (cropped)
A reel is an object around which a length of another material (usually long and flexible) is wound for storage (usually hose are wound around a reel). Generally a reel has a cylindrical core (known as a '' spool'') with flanges around the ends (known as the ''rims'') to retain the material wound around the core. In most cases the core is hollow in order to pass an axle and allow the reel to rotate like a wheel, and crank or handles may exist for manually turning the reel, while others are operated by (typically electric) motors. Construction The size of the core is dependent on several factors. A smaller core will obviously allow more material to be stored in a given space. However, there is a limit to how tightly the stored material can be wound without damaging it and this limits how small the core can be. Other issues affecting the core size include: * Mechanical strength of the core (especially with big reels) * Acceptable turning speed (for a given rate of material mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lifting Bag
A lifting bag is an item of diving equipment consisting of a robust and air-tight bag with straps, which is used to lift heavy objects underwater by means of the bag's buoyancy. The heavy object can either be moved horizontally underwater by the diver or sent unaccompanied to the surface. Lift bag appropriate capacity should match the task at hand. If the lift bag is grossly oversized a runaway or otherwise out of control ascent may result. Commercially available lifting bags may incorporate dump valves to allow the operator to control the buoyancy during ascent, but this is a hazardous operation with high risk of entanglement in an uncontrolled lift or sinking. If a single bag is insufficient, multiple bags may be used, and should be distributed to suit the load. There are also lifting bags used on land as short lift jacks for lifting cars or heavy loads or lifting bags which are used in machines as a type of pneumatic actuator which provides load over a large area. These lif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decompression Trapeze
There are several categories of decompression equipment used to help divers decompress, which is the process required to allow divers to return to the surface safely after spending time underwater at higher ambient pressures. Decompression obligation for a given dive profile must be calculated and monitored to ensure that the risk of decompression sickness is controlled. Some equipment is specifically for these functions, both during planning before the dive and during the dive. Other equipment is used to mark the underwater position of the diver, as a position reference in low visibility or currents, or to assist the diver's ascent and control the depth. Decompression may be shortened ("accelerated") by breathing an oxygen-rich "decompression gas" such as a nitrox blend or pure oxygen. The high partial pressure of oxygen in such decompression mixes produces the effect known as the oxygen window. This decompression gas is often carried by scuba divers in side-slung cylinder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decompression Equipment
There are several categories of decompression equipment used to help divers decompress, which is the process required to allow divers to return to the surface safely after spending time underwater at higher ambient pressures. Decompression obligation for a given dive profile must be calculated and monitored to ensure that the risk of decompression sickness is controlled. Some equipment is specifically for these functions, both during planning before the dive and during the dive. Other equipment is used to mark the underwater position of the diver, as a position reference in low visibility or currents, or to assist the diver's ascent and control the depth. Decompression may be shortened ("accelerated") by breathing an oxygen-rich "decompression gas" such as a nitrox blend or pure oxygen. The high partial pressure of oxygen in such decompression mixes produces the effect known as the oxygen window. This decompression gas is often carried by scuba divers in side-slung cylinder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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