Glossary of SCUBA Diving - I

I

ICD

Isobaric counterdiffusion: The diffusion of gases in opposite directions caused by a change in the composition of the external ambient gas or breathing gas without change in the ambient pressure.

IDRF

International Diving Regulators Forum: A voluntary group of diving regulators and certifying agencies formed to work together toward mutual recognition and to identify and implement best practices in diver training with the object of harmonizing cross border diver training standards outside Europe. Members include Australia, Canada, France, Norway, South Africa and United Kingdom..

IDSA

International Diving Schools Association: Formed with the primary purpose of developing common internationional diving standards for all occupational divers, Offshore, Inshore and Inland, and specialist related non-diving qualifications e.g. Supervisor, DMT and LST..

IMCA

International Marine Contractors Association.

inert gas

Further information: Decompression (diving)#Inert gas uptake (Ingassing)

A gas which is not metabolically active, used to dilute the breathing gas.

ingassing

Further information: Decompression (diving)#Inert gas uptake (Ingassing)

Inert gas uptake in body tissues during a dive or other hyperbaric exposure.

inherent unsaturation

Further information: Decompression (diving)#Inherent unsaturation

Metabolic reduction of total gas pressure in the tissues.

inshore diver

Colloquial term for a diver who works on inland dive sites or coastal waters not associated with the oil and gas industry. also referred to as "civils" as much of this work is connected with civil engineering works.

internal condition of cylinder

The state of the internal surface of a cylinder regarding corrosion, contamination and cracking.

interstitial emphysema

Gas trapped in the spaces between organs after lung barotrauma.