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Dive Adventures Scuba Glossary is for scuba divers and anyone else interested in scuba diving terminology. To find the scuba glossary term that you are looking for click on the letters below to display the scuba glossary terms that begin with that letter. If you feel that we have missed a term from our scuba glossary or would like a term added to our scuba glossary please contact us so that we can add that term to our scuba glossary. Dive Adventures thanks you for visiting our scuba glossary and helping us to make it better for other scuba divers and those interested in scuba diving terminology Optionally you may select "All Terms" to display the entire list of terms from our scuba glossary database.
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Abdominal hernia
A weakness of the abdominal wall through which the intestines or other intraabdominal contents protrude. Dangerous to a diver if a loop of air-containing intestine is trapped outside the abdomen.
Pressure calculated by using a vacuum as the zero point and including the gauge and atmospheric pressure in the calculation.
Actual bottom time (ABT)
Total elapsed time in minutes from leaving the surface until ascent is initiated.
Adjustable buoyancy life jacket
Also known as ABLJ or horse collar buoyancy compensator. A combination of buoyancy compensator and inflatable life jacket worn on the chest and round the neck.
A hormone secreted by the adrenal gland into the circulatory system which stimulates the heart, blood vessels and respiratory system.
Australian Diver Accreditation Scheme: An international commercial and occupational diver certification scheme.
Automatic Diluent Valve: A demand valve set into the breathing loop of a rebreather to inject diluent gas into the loop when the loop volume falls and there is not enough gas for inhalation.
Abbreviation for arterial gas embolism.
A gas mixture containing 21% oxygen, 78% nitrogen, and 1% other gasses (mainly argon); compressed air is used for recreational scuba diving.
Air compressor
A machine that compresses or pressurizes air; for scuba purposes, air is compressed from the atmospheric level (14.7 psi at sea level) to the capacity of the tank, usually between 2500-3000 psi.
Air Consumption
The depletion of breathing gas by a diver during the course of a dive.
Air Dome
A section of cave which traps air or other gas at the top. This gas is not directly connected to the surface.
Air embolism
A condition that occurs when air enters the bloodstream through ruptured alveoli into the pulmonary capillaries. The air in the bloodstream then forms bubbles, which can block blood flow to the body's tissues.
Air pressure
The force per unit area exerted by the weight of air; at sea level the air pressure is 14.7 psi. (air pressure decreases with altitude.)
A device based on a pipe, used in by divers to suck small objects, sand and mud from the sea bed and to transport the resulting debris upwards and away from its source. Air is injected into the lower end of the pipe and the rising bubbles entrain water and cause an upward flow which draws the material from the bottom along.
algal bloom
A rapid increase or accumulation in the population of algae (typically microscopic) in an aquatic system. Some blooms may be recognized by discoloration of the water resulting from the high density of pigmented cells. Visibility can be severely impaired over a period of hours to days. Sometimes refered as a Red Tide.
A set of equations incorporated into diving computers in order to compute nitrogen uptake and elimination from changes in depth and elapsed time.
Alpha flag
an International maritime signal flag, meaning, 'Diver down, keep clear'.
Alternate air source
A redundant air supply. A device a diver can use in place of the primary regulator, in order to make an safe ascent while still breathing normally. This can be either an octopus second stage or a separate tank and regulator, sometimes called a pony tank.
Alternoberic Vertigo
Un-even release of pressure from the inner ear. Causing vertigo, dizziness and spins.
altitude diving
Diving at a location where the water surface is at an altitude which requires modification of decompression schedules, (more than about 300 m (980 ft) above sea level.
altitude sickness
An illness brought on by the sudden reduction in pressure of ascent to altitude.
Air sac at the terminus of a bronchus where oxygen and carbon dioxide transfer occurs.
Ambient Light
It is the available sunlight underwater used as a source of illumination.
Ambient pressure
The surrounding pressure; on land, comes from the weight of the atmosphere (see air pressure), at depth, comes from the weight of the water plus the weight of the atmosphere. One atmospere is about 14.7 pounds of pressure per square inch.
Analog instrument
Device that uses a needle moving around a dial to provide information.
Anchor Line
A rope, cable or chain that attaches a boat to its anchor.
American Nitrox Divers Incorporated
Any reduction in the oxygen carrying capacity of the red blood cells.
A medical condition caused by a severe lack of oxygen in the body.
Medications that reduce the clotting ability of the blood. Particularly dangerous to divers due to barotrauma of air-filled body cavities.
An impairment of language ability which may range from having difficulty remembering words to being completely unable to speak, read, or write.
Aqua Lung
The first self-contained-underwater-breathing-apparatus that used compressed air and a two-stage on demand regulator. The aqua lung was designed by Jacques Cousteau and Emile Gagnan.
AR vest
A waistcoat (vest) style harness of heavy cloth with strong adjustable webbing straps so that the diver can not slide out under any predictable circumstance.
Archimedes principle
Any object wholly or partly immersed in fluid will be buoyed up by a force equal to the weight of the fluid displaced by the object.
An inert gas that makes up less than one percent of air (sometimes used as a dry suit gas).
Irregularities in the rhythm and rate of the heart, particularly dangerous to divers due to the underwater environment.
arterial bubble model
Decompression model in which the filtering capacity of the lung is assumed to have a threshold radius of the size of a red blood cell and sufficiently small decompression bubbles can pass to the arterial side, especially during the initial phase of ascent.
Arterial gas embolism
The condition characterized by bubble(s) of air from a ruptured lung segment under pressure; the bubbles enter the pulmonary circulation and travel to the arterial circulation, where they may cause a stroke.
Artificial Respiration
any means by which an alternating increase and decrease in chest volume is artificially created while maintaining an open airway in mouth and nose passages; mouth to mouth, mouth to nose and mouth to snorkel resuscitation are examples.
Artificial Spit
Small bottles of "special" liquid used by divers to keep their masks defogged. There are many diffrent manufactures that offer a gel, paste or spray.
Ascent Bottle
An extra cylinder of air used on deep dives to allow decompression stops without fear of running out of air.
Ascent Bottle
An extra cylinder of air used on deep dives to allow decompression stops without fear of running out of air. They come in many different sizes from 6 c.f. to a full 80 c.f. tank.
Ascent rate
The rate at which depth is reduced at the end of a dive. An important component of decompression.
Ascent/Decent line
Line suspended from a boat or a buoy for a diver to use to control their rate of ascent or descent.
A common condition manifested by narrowing of air passages within the lungs. One reason for the narrowing is excess mucous in the airway.
Atmosphere absolute; 1 ata is the atmospheric pressure at sea level; is measured with a barometer.
The blanket of air surrounding the earth, from sea level to outer space. Also, a unit of pressure; "one atmospheres is pressure of the atmosphere at sea level, I.e., 760 mm Hg. Two atmosphere is twice this pressure, 1520 mm Hg, etc. Abbreviated atm.
Atmosphere Absolute
The ambient pressure including the air column over the water. The air column = 1 atm. at sea level. In sea water, another atmosphere is added each 33 FSW (Feet of Sea Water) . There is an increase in pressure per foot of sea water equivalent to 1/33 or .03030303 . So ATA may be calculated by multiplying the depth (FSW) by .0303030 and then adding 1 for the air above the water. i.e. the ATA at 46 FSW = (46 * .0303030) + 1 = 2.3939 ATA. to convert ATA to FSW. ATA - 1 * 33 = FSW.
Atmospheric pressure
Pressure of the atmosphere at a given altitude or location.
Australian Underwater Federation
Aquatic World Awareness, Responsibility and Education. A PADI nonprofit environmental foundation that provides financial support for aquatic preservation endeavors, develops conservation-oriented educational materials and initiates public awareness campaigns.
Axial flow scrubber
An axial scrubber is a scrubber design in which the breathing gases move from top to bottom (or vise-versa) through the scrubber.

There are 53 scuba glossary terms listed.

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