Index of underwater diving: F–K

The following index is provided as an overview of and topical guide to underwater diving: Links to articles and redirects to sections of articles which provide information on each topic are listed with a short description of the topic. When there is more than one article with information on a topic, the most relevant is usually listed, and it may be cross-linked to further information from the linked page or section.

Underwater diving can be described as all of the following:

A human activity – intentional, purposive, conscious and subjectively meaningful sequence of actions. Underwater diving is practiced as part of an occupation, or for recreation, where the practitioner submerges below the surface of the water or other liquid for a period which may range between seconds to order of a day at a time, either exposed to the ambient pressure or isolated by a pressure resistant suit, to interact with the underwater environment for pleasure, competitive sport, or as a means to reach a work site for profit or in the pursuit of knowledge, and may use no equipment at all, or a wide range of equipment which may include breathing apparatus, environmental protective clothing, aids to vision, communication, propulsion, maneuverability, buoyancy control and safety equipment, and tools for the task at hand.

There are seven sub-indexes, listed here. The tables of content should link between them automatically:

F

Contents: Top	0–9	A	B	C	D	E	F	G	H	I	J	K	L	M	N	O	P	Q	R	S	T	U	V	W	X	Y	Z

Section contents: Top of section, Fa, Fe, Fi, Fl–Fn, Fo, Fr, Fu

Fa

Faber Industrie S.p.A., also known as Faber Cylinders – Italian manufacturer of high pressure gas storage cylinders
Faceplate (diving) – Transparent viewport on the front of a diving helmet or full-face mask
Fatal scuba diving incidents – Deaths occurring while scuba diving or as a consequence of scuba diving

Fe

Section contents: Top of section, Fa, Fe, Fi, Fl–Fn, Fo, Fr, Fu

Feather breathing – Technique for minimising gas loss during some regulator malfunctions
Federación Española de Actividades Subacuáticas (FEDAS) – Spanish national federation for underwater activities, affiliated to CMAS
Fédération Française d'Études et de Sports Sous-Marins (FFESSM) – French diver training and certification agency
Federazione Italiana Attività Subacquee (FIAS) – Italian non-profit recreational diver training organisation affiliated to CMAS
Feet fresh water – Unit of pressure equal to 1/34 atm.
Fenzy – French manufacturer of industrial and diving breathing equipment
Fernez, Maurice – French inventor and pioneer in underwater breathing apparatus
Ferraro, Luigi – Officer of the Royal Italian Navy and pioneer of Italian submarine warfare

Fi

Section contents: Top of section, Fa, Fe, Fi, Fl–Fn, Fo, Fr, Fu

Fibre wound composite cylinder – Pressure vessel with fibre structural reinforcement
Fick's laws of diffusion – Mathematical descriptions of molecular diffusion
Fife, William Paul – US Air Force officer and hyperbaric medicine researcher
Filling whip – High pressure hose for filling compressed gas cylinders
Fin retainer – Rubber straps for securing swimfins to the feet
Finning technique – Skills used by divers and surface swimmers using swimfins
Finswimming – Competitive watersport using swimfins for propulsion
Finswimming at the 2001 World Games – Competition held in Akita, Japan
Finswimming at the 2001 World Games – Men's 50 m apnoea – Competition held in Akita, Japan
Finswimming at the 2005 World Games – Men's 50 m apnoea – Competition held in Duisburg, Germany
Finswimming at the 2009 Asian Indoor Games – Competition held in Mỹ Đình National Aquatics Sports Complex, Hanoi, Vietnam
Finswimming at the 2009 World Games – International competition in Kaohsiung
Finswimming at the 2009 World Games – Men's 50 m apnoea – Event in Kaohsiung, Taiwan
Finswimming at the 2011 SEA Games – Watersport competition in Palembang, Indonesia
Finswimming at the 2021 SEA Games – Competition at Mỹ Đình Aquatics Center in Hanoi, Vietnam
Finswimming at the 2023 SEA Games – Competitions held at Phnom Penh, Cambodia
Finswimming at the World Games – Trend sport at the World Games
Finswimming in Australia – Competitive watersport
Finswimming in the United Kingdom – Competitive watersport
Finswimming in the United States – Competitive watersport
Finswimming World Championships – International event for the underwater sport of finswimming
First aid – Emergency first response medical treatment
Fischer, George R. – American underwater archaeologist
Fitness to dive, also known as fitness for diving – Medical fitness to function underwater

Fl–Fn

Section contents: Top of section, Fa, Fe, Fi, Fl–Fn, Fo, Fr, Fu

Fleuss, Henry – British inventor of diving equipment (1851 – 1933)
Flicker fusion threshold – Concept in the psychophysics of vision
Flushing the loop – Rebreather diving safety procedure
Flying after diving – Precautions against decompression sickness when ascending to altitude after diving
FNRS-2 – First bathyscaphe
FNRS-3 – Bathyscaphe of the French Navy

Fo

Section contents: Top of section, Fa, Fe, Fi, Fl–Fn, Fo, Fr, Fu

Force – Influence that can change motion of an object
Formoza Military Unit – Polish Special Forces unit
Forward dive profile – Repetitive dive shallower than the preceding dive

Fr

Section contents: Top of section, Fa, Fe, Fi, Fl–Fn, Fo, Fr, Fu

Fraction of inspired oxygen – Volumetric proportion of oxygen to other constituents in a breathing gas
Franzén, Anders – Swedish marine technician and amateur naval archaeologist
Free immersion apnea – Human-powered freediving discipline
Free-flow diving helmet, also known as Free-flow helmet – Helmet which supplies a continuous flow of air to the diver
Freediving – Underwater diving without breathing apparatus
Freediving blackout – Loss of consciousness caused by cerebral hypoxia towards the end of a breath-hold dive
Freediving blackout of ascent – Hypoxic blackout while ascending from a deep breathhold dive
Freediving computer – Worn unit for monitoring and recording freedive data
Freediving training agency, also known as Freediver training agency – Organisation for training and certifying the competence of freedivers
Freeflow – A state of continuous flow of breathing gas in an underwater breathing apparatus
Free-flow breathing apparatus – Equipment which provides a constant flow of breathing gas
French commando frogmen – Combat swimmer unit of the French Navy
Frenzel maneuver – Ear equalization technique originally developed for dive bomber pilots
Fresh gas flow (disambiguation) – Gas added to the recycled gas of a rebreather or anesthetic machine
Freshwater diving – Underwater diving in fresh water
Freshwater diving environment – Type of underwater diving environment
Frog kick – Finning propulsion kick used particularly by cave and wreck divers
Frogman – Tactical scuba diver
Frogman Corps (Denmark) – Danish maritime special operations unit
FROGS (Full Range Oxygen Gas System) – Closed circuit oxygen diving rebreather

Fu

Section contents: Top of section, Fa, Fe, Fi, Fl–Fn, Fo, Fr, Fu

Fuerzas Especiales – Special forces unit of the Mexican Navy
Fukuryu – Japanese divers intended to manually detonate mines on invading ships
Full-face diving mask – Diving mask that covers the mouth as well as the eyes and nose
Full facepiece – User respiratory inteface with breathing apparatus that covers the nose, mouth and eyes
Full-face snorkel mask – Breathing apparatus for surface swimming
Full ocean depth – Maximum known depth in the ocean

G

Contents: Top	0–9	A	B	C	D	E	F	G	H	I	J	K	L	M	N	O	P	Q	R	S	T	U	V	W	X	Y	Z

Section contents: Top of section, Ga, Ge, Gl, Go–Gp, Gr, Gu, Gy

Ga

Gaiters (diving) – Accessories used to restrict volume of a dry suit over the lower legs
Gap line, also known as jump line – Line laid when crossing a gap between permanent cave lines
Gas blender – Person who blends breathing gas mixtures for scuba diving and fills diving cylinders
Gas blender level 1, also known as Nitrox blender – Person competent to mix nitrox for scuba divers
Gas blender level 2, also known as Trimix blender – Person competent to mix trimix for scuba divers
Gas blending – Producing special gas mixtures to specification
Gas blending for scuba diving – Mixing and filling cylinders with breathing gases for use when scuba diving
Gas booster – Machine to increase the pressure of compressed gas
Gas capacity – Amount of gas that can be stored in a container
Gas cylinder – Cylindrical container for storing pressurised gas
Gas cylinder bundle, also known as gas cylinder quad – Group of manifolded gas cylinders mounted on a transport frame
Gas endurance – The time a gas supply will last
Gas exchange – Process by which gases diffuse through a biological membrane
Gas extender – Type of semi-closed circuit diving rebreather
Gas-integrated dive computer – A dive computer that displays the pressure of breathing gas remaining in the cylinder
Gas laws – List of physical laws relates to gases
Gas man, also known as gas panel operator – Member of a surface-supplied diving team who operates the breathing gas panel
Gas matching – Ensuring that reserve breathing gas is sufficient to supply the dive buddy
Gas panel – Breathing gas distribution panel for surface-supplied diving
Gas panel operator, also known as gas man – Member of a surface-supplied diving team who operates the breathing gas panel
Gas-reclaim system – Equipment to recover exhaled gas from a diver to tecover the helium content
Gas storage bank – Manifolded group of gas storge cylinders
Gas storage cylinder – Container for storing pressurised gas
Gas storage quad – Group of similar size high pressure cylinders
Gas storage tube – Large volume, high pressure gas storage cylinder
Gas switch – Change of breathing gas mixture during a dive
Gas switching – Changing the breathing gas mixture during a dive
Gas toxicity – Dose dependent harmfulness of gases
Gay-Lussac's law – Relationship between pressure and temperature of a gas at constant volume

Ge

German commando frogmen – German postwar commando amphibious warfare force

Gl

Section contents: Top of section, Ga, Ge, Gl, Go–Gp, Gr, Gu, Gy

Global Explorer ROV – Deep water science and survey remotely operated vehicle
Global Underwater Explorers (GUE) – Recreational/technical scuba training and certification agency
Glossary of breathing apparatus terminology – Definitions of technical terms used in connection with breathing apparatus
Glossary of underwater diving terminology, also known as Glossary of underwater diving terms or Glossary of SCUBA diving – Definitions of technical terms, jargon, diver slang and acronyms used in underwater diving
Glossary of underwater diving terminology: A–C – Definitions of technical terms, jargon, diver slang and acronyms used in underwater diving
Glossary of underwater diving terminology: D–G – Definitions of technical terms, jargon, diver slang and acronyms used in underwater diving
Glossary of underwater diving terminology: H–O – Definitions of technical terms, jargon, diver slang and acronyms used in underwater diving
Glossary of underwater diving terminology: P–S – Definitions of technical terms, jargon, diver slang and acronyms used in underwater diving
Glossary of underwater diving terminology: T–Z – Definitions of technical terms, jargon, diver slang and acronyms used in underwater diving

Go–Gp

Section contents: Top of section, Ga, Ge, Gl, Go–Gp, Gr, Gu, Gy

Goldfinder – Autobiography of British diver and treasure hunter Keith Jessop
Gold line (diving) – Permanent main guide line in a cave
Gold Rush: White Water – American television series
Goldfish-class ROUV – Light class of Chinese remotely operated underwater vehicle
Goodman handle – Mounting which holds a dive light on the back of the diver's hand
Gorski (diving helmet) – Diving helmet brand owned by Aqualung Group
GPS sonobuoy, also known as GPS intelligent buoy – Acoustic positioning devices

Gr

Section contents: Top of section, Ga, Ge, Gl, Go–Gp, Gr, Gu, Gy

Gradient factor – Method for adjusting conservatism of decompression algorithms
Gradient factor in decompression modelling – A way for users to adjust the conservatism of a decompression algorithm in software
Green Fins – Organisation in South East Asia for preservation of coral reefs by improving diver behavior
GROM Military Unit – Polish special forces unit
GRUMEC, also known as Brazilian commando frogmen – Brazilian Navy special forces diving unit

Gu

Guide line – Line deployed by scuba divers for navigation

Gy

Gyrojet – Firearm that fires small rocket projectiles

H

Contents: Top	0–9	A	B	C	D	E	F	G	H	I	J	K	L	M	N	O	P	Q	R	S	T	U	V	W	X	Y	Z

Section contents: Top of section, Ha–Hb, He, Hi, Ho, Hu, Hy

Ha–Hb

Haenyeo – Female divers of Jeju, South Korea
Halcyon Dive Systems – American manufacturer of diving equipment
Halcyon PVR-BASC – Semi-closed circuit depth compensated passive addition diving rebreather
Halcyon RB80 – Non-depth-compensated passive addition semi-closed circuit rebreather
Haldane, John Scott – British physiologist and decompression researcher (1860–1936)
Haldane's decompression model – Decompression model developed by John Scott Haldane
Half + 15 bar – Rule of thumb for scuba gas management
Half mask – Diving mask covering the nose and eyes
Half time (physics) – The time taken for a quantity to decrease by half in an exponential decay process
Halocline – Stratification of a body of water due to salinity differences
Hamilton, Robert William Jr. – American physiologist and researcher in hyperbaric physiology.
Hand-held sonar – Ranging and imaging units for use by divers
Hand-off a cylinder – Transfer a scuba cylinder from one diver to another in the water
Hand-off cylinder – Scuba set that can be passed to another diver
Hang-off profile – Commercial dive profile to limit ingassing during idle periods
Hans Hass Award – Award in recognition of contribution made to the advancement of knowledge of the ocean
Hans Hass – Austrian biologist, film-maker, and underwater diving pioneer
Hawaiian sling – Simple form of underwater speargun
Hazard – Situation or object that can cause damage
Hazard analysis (HAZID) – Method for assessing risk
Hazard elimination – Hazard control by removing the hazard
Hazard substitution – Replacing a material or process with a lower risk alternative
Hazardous Materials Identification System – Numerical hazard rating using colour coded labels
Hazards of the aquatic environment – Hazards inherent to being underwater
Hazards of the diving environment – Dangerous conditions typical of places people dive
Hazards of the specific diving environment – Factors which vary between diving environments
Hazmat diver – Professional diver working in hazardous materials environments
Hazmat diving – Underwater diving in a known hazardous materials environment
Hazmat diving decontamination – Removing hazardous environmental contaminants from the diver after a dive
H-BRUV – Horizontally aligned baited remote underwater video

He

Section contents: Top of section, Ha–Hb, He, Hi, Ho, Hu, Hy

Health and Safety Executive (HSE) – United Kingdom government agency
Healthways (scuba gear company) – Defunct firm which made scuba gear
Heckler & Koch P11 – Five-barreled underwater rocket dart pistol
Heinke (diving equipment manufacturer) – British manufacturer of diving equipment
HeinrichsWeikamp – German manufacturer of dive computers and other electronics for recreational diving
Helgoland Habitat – Ambient pressure underwater habitat
Heliair – Breathing gas mixed from air and helium
Helicopter Aircrew Breathing Device, also known as helicopter escape set – Small scuba device for escape from ditched helicopters
Helicopter turn – Rotation about a vertical axis by an underwater diver using only fins
Heliox – A breathing gas mixed from helium and oxygen
Helium analyzer, also known as Helium analyser – Instrument to measure the concentration of helium in a gas mixture
Helium reclaim system – System for recovering exhaled breathing gas
Helium release valve – Feature on some watches for saturation diving
Helium speech unscrambler – Technology for reducing hyperbaric speech distortion
Helix Energy Solutions Group – Provider of offshore services and ROV operations
Helmet squeeze – Injury caused low pressure in diving helmet
Helmet weight – Ballast added to a diving helmet to prevent it from floating
Hempleman, Henry Valence – British decompression researcher
Henry's law – Gas law regarding proportionality of dissolved gas

Hi

Section contents: Top of section, Ha–Hb, He, #HiHi, Ho, Hu, Hy

Hierarchy of hazard controls – System used in industry to eliminate or minimize exposure to hazards
High energy coast – Shoreline exposed to high energy waves
High energy underwater environment – Underwater environment with high kinetic energy of the water
High pressure breathing air compressor – Machine to fill cylinders with atmospheric air at high pressure for breathing
High-pressure gas storage cylinder, also known as High pressure storage cylinder – Pressure vessel for storage of high pressure gas
High-pressure nervous syndrome – Disorder from breathing helium based gas
High-pressure water jetting – Cleaning method using very high pressure water jet
Hill, Leonard Erskine – British physiologist and diving physiology researcher
Hills, Brian Andrew – Physiologist who worked on decompression theory
History of decompression research and development – Chronological list of notable events in the history of diving decompression.
History of Diving Museum – Museum of underwater diving in Islamorada, Florida
History of scuba diving
History of underwater diving – Developments over time in the human activity

Ho

Section contents: Top of section, Ha–Hb, He, Hi, Ho, Hu, Hy

Hog looped – Scuba regulator long hose configuration
Hogarthian scuba configuration – Scuba harness arrangement developed by Bill Main
Hoke valve – Gas recirculation control valve on MK V helium hemet
Hookah (diving) – Basic surface supplied equipment using an air-line
Hookah diving – Underwater diving using a basic air hose from the surface
Hoppe-Seyler, Felix – German physiologist and chemist (1825–1895)
Hot stab – Type of subsea quick connector for offboard services
Hot water suit – A wetsuit with a supply of heated water to keep a diver warm
Hot water system (diving) – Water heating and supply system for hot-water diving suits

Hu

Section contents: Top of section, Ha–Hb, He, Hi, Ho, Hu, Hy

Huggins, Karl E. – American decompression researcher
Human factors in diving equipment design – Influence of the interaction between the user and the equipment on design
Human factors in diving safety – The influence of physical, cognitive and behavioral characteristics of divers on safety
Human factors in the design of diving equipment – Influence of the interaction between the user and the equipment on design
Human physiology of underwater diving, also known as Human physiology of diving – Influences of the underwater environment on the physiology of human divers
Human torpedo – Early form of diver propulsion vehicle

Hy

Section contents: Top of section, Ha–Hb, He, Hi, Ho, Hu, Hy

Hydraulic chainsaw – Chainsaw powered by a hydraulic motor
Hydreliox – Breathing gas mixture of hydrogen, helium, and oxygen
Hydrocleaning – Use of a water jet for cleaning hard surfaces
Hydrogen narcosis – Psychotropic state induced by breathing hydrogen at high partial pressures
Hydrogen sulfide – Poisonous, corrosive and flammable gas
Hydrophobe – Molecule or surface that has no attraction to water
HydroSpace Engineering – US manufacturer of decompression computers
Hydrostatic pressure – The static pressure exerted by the weight of the fluid column above the point
Hydrostatic test – Non-destructive test of pressure vessels
Hydrox (breathing gas) – Breathing gas mixture experimentally used for very deep diving
Hyperbaric escape capsule – Small hyperbaric evacuation unit that drifts until rescued
Hyperbaric evacuation – Emergency transport of people in a hyperbaric chamber
Hyperbaric evacuation and rescue – Emergency transport of divers under a decompression obligation to a place of safety
Hyperbaric evacuation facilities – Systems to evacuate saturation divers in an emergency
Hyperbaric evacuation system – Equipment for emergency transport of divers under pressure to a place of safety
Hyperbaric evacuation unit – Pressure vessel in which divers are transported under pressure in an emergency
Hyperbaric lifeboat – Lifeboat for transporting people under pressure
Hyperbaric medicine – Medical treatment at raised ambient pressure
Hyperbaric nursing – Nursing specialty involved with hyperbaric oxygen therapy
Hyperbaric oxygen treatment – Medical oxygen treatment at raised pressure
Hyperbaric oxygen treatment table – Planned hyperbaric exposure using oxygen breathing gas as medical treatment
Hyperbaric reception facility – Saturation facility on standby in case evacuation is necessary
Hyperbaric rescue – Emergency transport of people in a hyperbaric chamber
Hyperbaric rescue chamber – Hyperbaric chamber suitable for emergency transport of divers under pressure
Hyperbaric rescue vessel – Ship to recover hyperbaric evacuation units
Hyperbaric speech distortion – Speech distortion at high ambient pressure
Hyperbaric stretcher – Portable pressure vessel to transport a person under pressure.
Hyperbaric transport – Transportation under pressure greater than atmospheric
Hyperbaric transportation – Transport under pressure greater than atmospheric
Hyperbaric treatment – Medical treatment at raised ambient pressure
Hyperbaric treatment schedules – Planned hyperbaric exposure using a specified breathing gas as medical treatment
Hyperbaric treatment tables – Planned hyperbaric exposure using a specified breathing gas as medical treatment
Hyperbaric welding – Welding metal at elevated pressure
Hypercapnia – Abnormally high tissue carbon dioxide levels
Hyperoxia – Exposure of tissues to abnormally high concentrations of oxygen.
Hyperoxic breathing gas – Gas mixture with higher oxygen content than air
Hyperthermia – Elevated body temperature due to failed thermoregulation
Hyperventilation – Excessive breathing
Hyperventilation-induced blackout – Loss of consciousness caused by cerebral hypoxia towards the end of a breath-hold dive
Hypobaric decompression – Reduction in pressure to lower than normal sea level atmospheric pressure
Hypocapnia – State of reduced carbon dioxide in the blood
Hypothermia – Human body core temperature below 35 °C (95 °F)
Hypoventilation – Insufficient breathing
Hypoxia (medicine) – Medical condition of lack of oxygen in the tissues
Hypoxia of ascent – Loss of cosciousness during ascent from a breathhold dive
Hypoxic blackout – Loss of consciousness due to cerebral hypoxia
Hypoxic breathing gas – Gas mixture with lower oxygen content than air
Hypoxic trimix – Gas mixture of helium, nitrogen and insufficient oxygen to safely breathe at surface pressure
Hypoxic trimix diver – Recreational technical diving certification level

I

Contents: Top	0–9	A	B	C	D	E	F	G	H	I	J	K	L	M	N	O	P	Q	R	S	T	U	V	W	X	Y	Z

Section contents: Top of section, Ic, Id, Im, In, Ir–Is, It

Ic

Ice diving – Underwater diving under ice
Ichthyander Project – Soviet underwater habitat project of the 1960s
Ictineu 3 – Crewed submersible

Id

Section contents: Top of section, Ic, Id, Im, In, Ir–Is, It

IDA71 – Russian military rebreather for underwater and high altitude use
Ideal gas law – Equation of the state of a hypothetical ideal gas
IDRCF – International Diving Regulators and Certifiers Forum

Im

Section contents: Top of section, Ic, Id, Im, In, Ir–Is, It

IMCA – International trade association for the marine contracting industry
IMCA Code of Practice for Offshore Diving, also known as IMCA D014 – Guidance document for member organisations
IMCA Diving Supervisor's Manual, also known as IMCA D022 – Procedures endorsed by IMCA for offshore diving operations
IMCA Safety flash – Anonymised incident reports
Immersion finswimming – Competitive scuba watersport using swimfins for propulsion
Immersion finswimming with breathing apparatus – Competitive scuba watersport using swimfins for propulsion
Immersion pulmonary oedema – Body fluid accumulated in the lungs due to immersion in a liquid
Immersion response – The physiological responses to immersion of air-breathing vertebrates

In

Section contents: Top of section, Ic, Id, Im, In, Ir–Is, It

Incident pit – Conceptual model for explaining incident development and recovery
Independent doubles, also known as Independent twin cylinders – Two fully redundant back-mounted scuba sets with no cross-connection
Index of recreational dive sites – Alphabetical listing of articles on porular places for recreational diving
Index of underwater divers – Alphabetical listing of articles about underwater divers
Index of underwater diving – Alphabetical listings of underwater diving related topics
Industrie Werke Karlsruhe Aktiengesellschaft (IWKA) – German manufacturer of seamless steel gas cylinders
Inert gas counterdiffusion – Diffusion of one inert gas into body tissues while another inert gas is diffusing out
Ingassing – Uptake of gases by biological tissues
Inherent unsaturation – Physiological effect of oxygen metabolism on the total dissolved gas concentration in venous blood
Inland dive site – Sites in bodies of water inland of the sea coastline
Inland diving – Diving in waters inland of the coastal high water mark.
Inner ear barotrauma – Pressure injury to the inner ear
Inner ear decompression sickness – Medical condition caused by inert gas bubbles forming out of solution
Inshore diving – Diving in coastal territorial waters
Instinctive drowning response – Instinctive reaction that occurs in humans when close to drowning
Insulán, Stig – Inventor of an adjustable automatic exhaust valve for variable volume dry suits
Integrated Diver Display Mask – Diving half-mask with integrated head-up instrument display
Integrated weight system – Diver weights carried on the buoyancy compensator or safety harness
Integrated weights – Diving weights carried in pockets on the buoyancy compensator
Intelligent Water class AUV – Autonomous underwater vehicle for the People's Liberation Army Navy
International Association for Handicapped Divers (IAHD) – Non-profit organisation based in the Netherlands
International Association of Nitrox and Technical Divers (IANTD) – Recreational and technical scuba training and certification agency
International Bluewater Spearfishing Records Committee – Committee of special interest
International Coral Reef Society – Non-profit scientific society for the conservation of coral reefs.
International Divers Alert Network – Independently administered nonprofit DAN regional organizations
International Diving Institute – American commercial diver training school
International Diving Regulators and Certifiers Forum (IDRCF), also known as International Diving Regulators Forum – International forum of professional diver accreditation organisations
International Diving Schools Association (IDSA) – Organisation to develop common standards for commercial diver training
International Life Saving Federation – Umbrella organization of the national lifesaving organizations
International Marine Contractors Association (IMCA) – International trade association for the marine contracting industry
International Organization for Standardization (ISO) – International standards development organization
International Scuba Diving Hall of Fame – Annual event recognizing recreational scuba industry contributors
International Submarine Escape and Rescue Liaison Office – Organization that coordinates international submarine search and rescue operations.
International Underwater Cave Rescue and Recovery – Cave diving rescue/recovery organization
Interspiro – Swedish manufacturer of breathing apparatus
Interspiro DCSC – Military semi-closed circuit passive addition diving rebreather
Intervention AUV – Type of autonomous underwater vehicle capable of autonomous interventions
Intestinal squeeze – Injury to intestines by expanding gas during decompression
Introductory diving – Non-certification scuba diving experience
Introductory scuba experience – Non-certification scuba diving experience
Investigation of diving accidents – Forensic investigation of underwater diving accidents
In-water cleaning – Methods of removing contaminants from underwater surfaces
In-water recompression – In-water treatment for decompression sickness
In-water surface cleaning – Methods of removing contaminants from underwater surfaces
In-water recompression – In-water treatment for decompression sickness

Ir–Is

Section contents: Top of section, Ic, Id, Im, In, Ir–Is, It

iRobot Seaglider – Deep diving autonomous underwater vehicle for long term missions
iSimangaliso Marine Protected Area – Marine conservation area in northern kwaZulu-Natal in South Africa
Isobaric counterdiffusion – Gaseous diffusion through body tissue at constant total pressure
Isolation manifold – Upstream scuba manifold with a shut-off valve
Isolation-manifolded twin cylinders, also known as isolation-manifolded twin set – Scuba set with two back-mounted cylinders connected by a manifold with an isolation valve
ISO 24801 Recreational diving services — Requirements for the training of recreational scuba divers – International training standards for recreational scuba
ISO recreational diving training standards – Publications of the International Standards Organisation
Israeli Diving Federation (TIDF) – Israeli recreational diver training and certification agency

It

Italian auxiliary ship Olterra – Undercover Italian auxiliary ship from World War II

J

Contents: Top	0–9	A	B	C	D	E	F	G	H	I	J	K	L	M	N	O	P	Q	R	S	T	U	V	W	X	Y	Z

Jacket harness – Type of surface-supplied diving safety harness
Jackstay – Substantial line between two points used to guide or support
Jackstay (diving) – Substantial underwater guide line
Jackstay search – Underwater search along a laid down line
Jagdkommando – Austrian Armed Forces' Special Operations group
JAGO (German research submersible) – Crewed German research submersible
Jersey upline – A buoyed line serving as a position control during decompression
Jetsam Technologies – Manufacturer of manual closed circuit rebreathers
JIM suit – Type of atmospheric diving suit.
Job safety analysis (JSA) – Procedure to integrate safety practices into a particular task
Jocking harness, also known as jocking strap – System to manage buoyancy of a diver's helmet
Johnson Sea Link accident – Manned submersible incident in which two divers died
Jonline – A short line used by scuba divers to clip themselves to something
Josef Heiser – Austrian manufacturer of seamless steel gas cylinders
Jump camera – Camera triggered by landing on the bottom of a body of water
Jump jacket – Surface-supplied diving safety harness with buoyancy compensation
Jump line, also known as gap line – Line laid when crossing a gap between permanent cave lines
Jump spool – Diving navigation and safety equipment
Junior Open Water Diver – Entry level scuba certification for ages 10 to 14
Just culture – Balanced accountability for both individuals and the organization
J-valve – Type of scuba cylinder valve with reserve lever

K

Contents: Top	0–9	A	B	C	D	E	F	G	H	I	J	K	L	M	N	O	P	Q	R	S	T	U	V	W	X	Y	Z

Kaikō ROV – Japanese remotely operated underwater vehicle for deep sea exploration
Kaşif ROUV – Turkish remotely operated underwater vehicle
Klingert, Karl Heinrich – German mechanic and inventor of an early surface-supplied diving suit.
Karst Underwater Research – Non-profit organization that specializes in the research and documentation of karst aquifers
Kayak diving – Recreational diving from a canoe or kayak
Keel weight (diving) – Weight added to a diver's backplate
Kelly (gas storage) – Large volume high pressure gas storage tubes
Kilsby sinkhole – Sinkhole in Mount Gambier, Southern Australia
Kimiuo Aisek Memorial Museum – Museum in Chuuk State, Federated States of Micronesia
KISS (rebreather) – Manual closed circuit mixed gas rebreather
Kommando Spezialkräfte Marine, also known as Kampfschwimmer – German postwar commando amphibious warfare force
Kongsberg Mesotech – Manufacturer of sonar equipment for underwater imaging and detection
Konsul-class submersible – Russian Navy deep sea submergence vehicle
KOPASKA – Indonesian Navy special operations and demolition unit
Kreeft, Peter – 18th Century German inventor and diver
Kronan (ship) – Swedish Navy ship of the 1670s
Kursk submarine disaster salvage operation – Raising the wreck of a Russian nuclear submarine
K-valve – Plain single outlet scuba cylinder valve

Contents: Top	0–9	A	B	C	D	E	F	G	H	I	J	K	L	M	N	O	P	Q	R	S	T	U	V	W	X	Y	Z

F

Fa

Fe

Fi

Fl–Fn

Fo

Fr

Fu

G

Ga

Ge

Gl

Go–Gp

Gr

Gu

Gy

H

Ha–Hb

He

Hi

Ho

Hu

Hy

I

Ic

Id

Im

In

Ir–Is

It

J

K

See also