13. DEFINITION OF TERMS
AAUS - The American Academy of Underwater Sciences.

Air sharing - The sharing of an air supply between divers.

Bottom Time - The total elapsed time measured in minutes from the time when the diver leaves the surface in descent to the time that the diver begins a direct ascent to the surface.

Bounce Dive - A dive of relatively short duration. Generally less than 10 minutes.

Breath-hold Diving - A diving mode in which the diver uses no self-contained or surface-supplied air or oxygen supply.

Buddy Breathing - The sharing of a single air source between divers.

Buddy Diver - Second member of the dive team.

Buddy system -Two comparably equipped scuba divers in the water in constant communication.

Buoyant Ascent - An ascent made using some form of positive buoyancy.

Burst Pressure - The pressure at which a pressure containment device would fail structurally.

Certified Diver - A diver who holds a recognized valid certification from a organizational member or recognized certifying agency.

Closed Circuit Diving - Diving in which the breathing gas is recirculated, scrubbed, and rebreathed.

Controlled Ascent - Any one of several kinds of ascents including normal, swimming, and air sharing ascents where the diver(s) maintain control so a pause or stop can be made during the ascent.

Cylinder - A pressure vessel for the storage of gases.

Decompression Chamber - A pressure vessel for human occupancy. Also called a hyperbaric chamber or recompression chamber.

Decompression Sickness - A condition with a variety of symptoms which may result from gas and bubbles in the tissues of divers after pressure reduction.

Decompression Table - A profile or set of profiles of depth-time relationships for ascent rates and breathing mixtures to be followed after a specific depth-time exposure or exposures. These profiles are based on theoretically safe nitrogen/inert gas absorption and elimination times. (Also called dive tables.)

Dive - A descent into the water, an underwater diving activity utilizing compressed gas, an ascent, and return to the surface.

Dive Computer- A microprocessor based device which computes a diver's theoretical decompression status, in real time, by using pressure(depth) and time as input to a decompression model, or set of decompression tables, programmed into the device.

Dive Location - A surface or vessel from which a diving operation is conducted.

Dive Master - A certified diver with experience and training to conduct the diving operation and who has been designated to be in charge of the diving operation by the Diving Safety Officer. This term is interchangeable with "lead diver" as used in the AAUS manual.

Dive Site - The physical location of a diver during a dive.

Dive Platform - A surface or vessel from which a diving operation is conducted.

Diver - An individual in the water who uses apparatus which supplies breathing gas at ambient pressure.

Diver-Carried Reserve Breathing Gas - A diver-carried independent supply of air or mixed gas (as appropriate) sufficient under standard operating conditions to allow the diver to reach the surface, or another source of breathing gas, or to be reached by another diver.

Diver-In-Training - An individual gaining experience and training in additional diving activities under the supervision of a dive team member experienced in those activities.

Dive Tables - See "Decompression Tables".

Dive Team - Divers and support individuals who are exposed to or control the exposure of others to hyperbaric conditions.

Diving - see "Dive".

Diving Mode - The type of diving employed during a dive. For example: skin diving, SCUBA, surface-supplied air, hookah, saturation, closed circuit, etc.

Diving and Water Safety Control Board (DSCB)- The group of individuals who act as the official representative of the University in matters concerning the diving programs (see Sec. 1.3.2.3).

Diving Safety Officer (DSO) - The individual responsible for the safe conduct of the University Diving Programs (see Section 1.3.2.4).

Diving Supervisor - Divers with sufficient experience and demonstrated ability to supervise a new diver under openwater conditions for the purpose of completing training or certification dives.

DSCB - Diving and Water Safety Control Board.

Emergency Ascent - An ascent made under emergency conditions where the diver exceeds the normal ascent rate.

FSW - Feet of sea water, or equivalent static head.

Hookah Diving - A type of shallow water surface-supplied diving where the diver uses the second stage of a SCUBA regulator and hose connected to a surface air source.

Hyperbaric Chamber - See decompression chamber.

Hyperbaric Conditions - Pressure conditions in excess of normal atmospheric pressure.

Lead Diver - The certified scientific diver with experience and training to conduct the diving operation. This term is interchangeable with Dive Master.

Liveboating - The practice of supporting a diver from a vessel which is underway.

Maximum Working Pressure - The maximum pressure to which a pressure vessel may be exposed under standard operating conditions.

Mixed-Gas Diving - A diving mode in which the diver is supplied in the water with a breathing gas other than air.

MSW - Meters of sea water or equivalent static head.

No-Decompression Limits - The theoretical depth-time limits of a dive, specified by a table or model, from which a diver can return directly to the surface at a control rate without being required to spend time at shallower depths to allow inert gas to be eliminated from the body.

Normal Ascent - An ascent made with an adequate air supply at a rate of 60 feet per minute or less.

Open Circuit SCUBA - No portion of the breathing gas is rebreathed.

Organizational member - An organization which is a current member of the AAUS, and which has a program which adheres to the standards of the AAUS as set forth in the AAUS Standards for Scientific Diving Certification and Operation of Scientific Diving Programs.

Pressure-Related Injury - An injury resulting from pressure disequilibrium within the body as the result of hyperbaric exposure. Examples include: decompression sickness, pneumothorax, mediastinal emphysema, air embolism, subcutaneous emphysema, or ruptured eardrum.

Pressure Vessel - See cylinder.

Psig - pounds per square inch gauge.

Recompression Chamber - A pressure vessel for human occupancy such as a surface recompression chamber, closed bell, or deep diving systems used to recompress divers and to treat decompression sickness.

Recreational Diving - All diving conducted for leisure purposes and diving associated with the Physical Education curriculum (see section 8).

Reserve Breathing Gas - An emergency supply of breathing gas. A supply system of air or mixed gas (as appropriate) which is independent of the primary supply system and sufficient to support divers for ascent including any planned decompression stops.

Scientific Diver - A diver holding a current, valid scientific diving certificate or temporary scientific diving certificate as defined in section 5.

Scientific Diving - All diving performed by individuals necessary to and part of a scientific research, or educational activity in conjunction with a project or study under the jurisdiction of any public or private research or educational institution or similarly recognized organization, department, or groups.

Scientific Supervisor - Scientific personnel with experience and training to instruct and/or supervise the scientific techniques that are involved in the research operation.

Skin Diving - A diving mode in which the diver is equipped with mask, fins and snorkel, but which does not involve the use of compressed breathing gas as would be used in SCUBA or Surface Supplied Diving.

Scuba Diving - A diving mode independent of surface supply in which the diver uses open circuit self-contained underwater breathing apparatus.

Standard Operating Procedures (SOP) - Those rules, regulations, policies and procedures as are written and described in this manual, i.e. ECU Diving Manual.

Standby Diver - A diver at the dive location capable of rendering assistance to a diver in the water.

Surface Supplied Diving - A diving mode in which the diver in the water is supplied from the dive location with compressed gas for breathing.

Swimming Ascent - An ascent which can be done under normal or emergency conditions accomplished by simply swimming to the surface.

Umbilical - The composite hose bundle between a dive location and a diver or bell, or between a diver and a bell, which supplies a diver or bell with breathing gas, communications, power, or heat, as appropriate to the diving mode or conditions, and includes a safety line between the diver and the dive location.

University Auspices - Anything associated with the support, protection or patronage of or by ECU, including, but not limited to: occupation, research, education and training.

Working Pressure - The normal pressure at which the system is designed to operate.

DSM96

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