# Index of underwater diving: D–E

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:
There are seven sub-indexes, listed here. The tables of content should link between them automatically:
* Index of underwater diving: A–C
* Index of underwater diving: D–E
* Index of underwater diving: F–K
* Index of underwater diving: L–N
* Index of underwater diving: O–R
* Index of underwater diving: S
* Index of underwater diving: T–Z

## D

| 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, Da–Dd, De, Di, Do, Dr, Ds, Du–Dw, Dy

### Da–Dd

* Dacor (scuba diving) – Former American diving equipment manufacturer
* Dalmine (cylinders) – Italian manufacturer of seamless steel gas cylinders
* Dalton's law – Empirical law of partial pressures
* Damant, Guybon Chesney Castell – English physiologist, diver, royal navy officer, and researcher
* DAN Asia-Pacific – Regional organisation of the Divers Alert Network
* DAN Brasil – Regional organisation of the Divers Alert Network
* DAN Europe – Regional organisation of the Divers Alert Network
* DAN Japan – Regional organisation of the Divers Alert Network
* DAN Southern Africa – Regional organisation of the Divers Alert Network
* DAN World – Organisation of the Divers Alert Network covering other regions
* The Darkness Beckons – History of UK cave diving by Martyn Farr
* Darwin's Arch – Rock arch near Darwin Island (collapsed 2021)
* Davis Submerged Escape Apparatus – Early submarine escape oxygen rebreather also used for shallow water diving.
* Davis, Robert – English inventor and manufacturer of underwater breathing apparatus
* Day boat (diving), also known as day dive boat – Diving excursion boat without overnight accommodation
* Day, John – First recorded death in a diving chamber
* D-BRUV – Downward looking baited remote underwater video
* DCIEM decompression tables – Decompression tables based on the Kidd-Stubbs model
* DDRC Healthcare – British hyperbaric medical organisation

### De

Section contents: Top of section, Da–Dd, De, Di, Do, Dr, Ds, Du–Dw, Dy
* Dead space (physiology) – Inhaled air not part of gas exchange
* Deadspace (in breathing apparatus) – Inhaled air not part of gas exchange
* Deadweight anchor – Anchor that relies on weight and friction for holding
* Deane, Charles Anthony – Pioneering diving engineer and inventor of a surface supplied diving helmet
* Deane, John – Joint inventor of the diving helmet
* Death of Linnea Mills – Death of a recreational scuba diver during training
* Decima Flottiglia MAS – Italian naval commando frogman unit of the Fascist era
* Deck decompression chamber – Hyperbaric chamber suitable for surface decompression or emergency use at a dive site
* Decompression algorithm – Procedure to calculate the decompression needed for a given dive profile
* Decompression bar – Horizontal bar suspended below the water surface at a decompression stop
* Decompression buoy – Inflatable surface marker buoy deployed from underwater
* Decompression ceiling – Theoretic limit to ascent with a decompression obligation
* Decompression chamber – Any pressure vessel for human occupancy used to decompress a person
* Decompression chamber operation – Operation of a hyperbaric chamber in support of underwater diving
* Decompression computer, also known as dive computer – Instrument to calculate decompression status in real time
* Decompression cylinder – Scuba cylinder carrying decompression gas
* Decompression (diving) – Pressure reduction and its effects during ascent from depth
* Decompression emergency – Contingency threatening the diver's health during decompression
* Decompression equipment – Equipment used by divers to facilitate decompression
* Decompression gas – Oxygen-rich gas used for accelerated decompression
* Decompression illness – Disorders arising from ambient pressure reduction
* Decompression model – Conceptual explanation forf decompression that helps formulate predictions
* Decompression modelling – Using conceptual explanation forf decompression to help formulate predictions
* Decompression monitoring equipment – Equipment for monitoring depth and run time of a dive, and decompression status
* Decompression obligation – Physiological requirement for decompression to reduce risk of injury
* Decompression planning – Estimating the decompression for a planned dive profile
* Decompression practice – Techniques and procedures for safe decompression of divers
* Decompression schedule – A specified ascent rate and series of increasingly shallower decompression stops
* Decompression sickness – Disorder caused by dissolved gases forming bubbles in tissues
* Decompression status – The theoretical level of inert gas content of the body tissues
* Decompression status monitoring – Keeping appraised of whether and how much decompression is required by a diver
* Decompression stop – Pause during tascent from a dive to release dissolved inert gas in tissues
* Decompression stress – Combined influences on formation of decompression gas bubbles
* Decompression theory – Theoretical modelling of decompression physiology
* Decompression trapeze – Horizontal bars suspended at decompression stop depths
* de Corlieu, Louis – French naval officer and inventor of the swimfin
* Deep air diving – Underwater diving beyond accepted limits for breathing air
* Deep air diving blackout – Loss of consciousness due to extreme nitrogen narcosis
* Deepblu – Manufacturer of dive computers
* DeepC – Autonomous underwater vehicle powered by a fuel cell
* Deep Diver – Research submersible
* Deep diving – Underwater diving to a depth beyond the norm accepted by the associated community
* Deep Drone – US Navy remotely operated underwater vehicle
* DeepFlight Merlin – 3-seater wet sub diver propulsion vehicle
* Deepsea Challenger – Submersible that traveled to the Challenger Deep
* Deepspot – Deep swimming pool in Poland
* Deep-submergence rescue vehicle – Submersible used for rescue of people from disabled submarines and submersibles
* Deep stop – Additional stop deeper than the first obligatory decompression stop
* Deep water blackout (disambiguation)
* Deep water submersible – Self-propelled deep-diving crewed submersible
* Defence Diving School – Diver training centre in Portsmouth Harbour, UK
* Defense against swimmer incursions – Methods of protection from incursions by divers and swimmers
* Defence and Civil Institute of Environmental Medicine – Canadian research institute which produced decompression tables
* Delta-P (hazard), also known as ΔP, δp – Underwater hazard due to strong localised pressure differential
* Delta P Technology – Technical dive computer manufacturer
* Demand controlled breathing apparatus – Equipment that supplied breathing gas only when required
* Demand helmet – Diving helmet supplied with gas through a demand valve
* Demand valve oxygen therapy – Use of high-inhalation concentrations of oxygen as medical treatment
* Demister (scuba) – Surfactant used to prevent condensation of water droplets on a mask or helmet viewport
* Demobilise (diving) – The dismantling, packing and transport back to storage of the dive spread
* Demographics of recreational diving – Population distribution of recreational divers
* Demographics of scientific divers – Population distribution of scientific divers
* Denayrouze, Auguste – French inventor of a demand air supply regulator for underwater diving
* Dental barotrauma – Damage to a tooth caused by a change of ambient pressure
* Department of Employment and Labour – Department of the South African government responsible for matters related to employment
* Deployment of a decompression buoy – Launching a delayed surface marker buoy
* Depth blackout – Loss of consciousness due to deep diving while breathing air
* Depth gauge – Instrument that indicates depth below a reference surface
* DEPTHX – Autonomous underwater vehicle for exploring sinkholes in Mexico
* Descending and ascending (diving) – Procedures for safe ascent and descent in underwater diving
* DESCO – American manufacturer of commercial diving equipment
* DESCO air hat – Surface -supplied diving free-flow helmet
* Developed pressure – Working pressure corrected for actual temperature

### Di

Section contents: Top of section, Da–Dd, De, Di, Do, Dr, Ds, Du–Dw, Dy
* Diamond Reef System – System for training divers in buoyancy, trim and maneuvering skills
* Diffuser (breathing set part) – Component fitted over the exhaust outlet to break up the exhaled gas
* Diffusion – Transport of dissolved species from the highest to the lowest concentration region
* Diluent flush, also known as dil flush – Rebreather diving safety procedure
* Diluent gas – Metabolically inert gas in a breathing mixture
* DIN 477 – German standard for gas cylinder valves
* DIN 7876 – German standard for manufacture of swimfins
* DIN connection – Scuba cylinder standard valve connection
* DIR philosophy – An approach to scuba diving safety
* Directed search – Underwater search directed from the surface
* Disappearance of Ben McDaniel – Scuba diver who disappeared during or after a cave dive
* Distance line, also known as guide line – Line deployed by scuba divers for navigation
* Diuresis – Increase in urine production
* Dive bag – Container for transporting personal diving equipment
* Dive boat – Boat used for the support of scuba diving operations
* Dive boat operation – Operational procedures for a boat supporting diving
* Dive boat skipper – Person in command of a dive boat
* Dive briefing – Meeting of the dive team to discuss details before the diving operation
* Dive center – Service organisation providing recreational diver training, equipment and dive outings
* Dive computer, also known as Decompression computer – Instrument to calculate decompression status in real time
* Dive computer algorithm – Program for calculating decompression status and an acceptably safe ascent profile
* Dive computer lockout – Programmed shutdown of decompression information
* Dive cylinder – Cylinder to supply breathing gas for divers
* Dive guide (disambiguation)
* Dive guide (publication) – Travel guides for recreational diving
* Dive leader, also known as dive guide, divemaster – Recreational diving certification and role
* Dive Leader – Recreational diving certification
* Dive light – Light used underwater by a diver
* Dive location – Location at which a dive may occur
* Dive log – Record of diving history of an underwater diver
* Divemaster – Recreational dive leader certification and role
* Dive plan – Product of dive planning activity
* Dive planning – The process of planning an underwater diving operation
* Dive profile – Diver's pressure exposure over the time of a dive
* Dive resort – Recreational diving service provider with accommodation
* Dive school – Establishment for diver training
* Dive site – Place at which underwater diving occurs
* Dive skins – Thin exposure suit to protect the skin in warm water
* Divesoft – Manufacturer of diving rebreathers and accessories
* Dive spool – Simple flanged cylindrical line-holder
* Dive spot – Location at which a dive may occur
* Dive suit – Garment or device designed to protect a diver from the underwater environment
* Dive supervisor – Recreational dive group leader responsible for safety
* Dive Supervisor – Recreational dive leadership certification
* Dive tables – Data used to determine a decompression schedule for a given dive profile and breathing gas
* Dive team – A group of people working together to enhance dive safety and achieve a task
* Dive timer – Electronic timer that automatically records the run time of a dive
* Dive weights – Ballast weights carried by divers to counteract buoyancy of equipment
* Dive-float – Small buoy towed by an underwater diver to indicate presence
* Dive supervision – The work of the manager of a professional diving team
* Dive/surface valve (DSV) – Valve on a rebreather mouthpiece to isolate the breathing loop when not in use
* Diver, The – Sculpture by John Kaufman
* Diver (United States Navy) – US Navy personnel qualified in underwater diving and salvage
* Diver certification – Certification as competent to dive to a specified standard
* Diver certification agency – Organisation which issues certification for competence in diving skills
* Diver certification equivalences – Comparison between certifications by different agencies
* Diver certification organisation – Organisation that issues certificates of competence to underwater divers
* Diver communications – Methods used by underwater divers to communicate
* Diver detection sonar – Acoustic location systems to detect divers and submerged swimmer delivery vehicles
* Diver down flag – Flag signal indicating divers are in the water nearby
* Diver excursion – Diver temporary movement away from a reference point
* Diver hand signals – Hand signals used for communication with divers
* Diver lift – Movable platform for lifting a diver from the water to deck level
* Diver lock-out compartment – Airlock used for underwater access to a submarine
* Diver lock-out submersible – Manned submersible with an airlock for underwater use
* Diver medical technician – Paramedic with special training in diving medical emergencies
* Diver navigation – Underwater navigation by scuba divers
* Diver organisations – Membership organisations of underwater divers
* Diver propulsion vehicle (DPV) – Powered device for diver mobility and range extension
* Diver rescue – Rescue of a distressed or incapacitated diver
* Diver safety – Risk management by and for the diver
* Diver searches – Underwater searches carried out by divers.
* Diver sled – Unpowered steerable creboards towed by a surface boat
* Diver surface detection aids – Equipment to make a surfaced diver easier to find
* Diver training – Processes to develop the skills and knowledge to dive safely underwater
* Diver training manual – Documentary training aid used for training underwater divers
* Diver training agency – Organisation for training and certifying underwater divers
* Diver training organization – Organization which provides training in diving skills or knowledge
* Diver training referral system – System for allowing training to be completed by another instructor
* Diver training standard – Document describing requirements of a diver training programme
* Diver training tank – Tank of water to practice diving skills
* Diver trim – Balance and orientation skills of an underwater diver
* Diver voice communications – Protocol for spoken communications in diving operations
* Diver voice communication protocol – Procedures for effective communication with divers
* Diver weighting system – Ballast carried by underwater divers to counteract buoyancy
* Diver's air pump – Manually powered surface air supply for divers
* Divers Academy International – Technical educational institution in New Jersey that offers training in commercial diving
* Divers Alert Network (DAN) – Group for improving diving safety
* Divers Alert Network America – A not-for-profit diving safety organization based in the US
* Divers Alert Network Asia-Pacific – A not-for-profit diving safety organization based in Australia
* Divers Alert Network Europe – A not-for-profit diving safety organization based in Europe
* Divers Alert Network publications
* Divers Alert Network Southern Africa (DAN-SA) – A public benefit diving safety organization based in South Africa
* Diver's attendant – Assistant for a diver
* Diver's cutting tool – A tool to assist in extricating the diver from entrapment by lines or nets
* Diver's harness – Item fastened around a diver which allows the diver to be lifted
* Divers Institute of Technology – Private, commercial educational institution for the training of commercial divers
* Diver's knife – A tool to assist in extricating the diver from entrapment by lines or nets
* Diver's logbook – Record of diving history of an underwater diver
* Diversnight – Annual recreational night diving festival.
* Diver's pump – Manually powered surface air supply for divers
* Diver's safety harness – Harness suitable for lifting a diver out of the water
* Diver's telephone – Hard wired diver communications equipment
* Diver's tender – Assistant to a diver
* Diver's umbilical – Hose supplying breathing gas to a diver from the support platform
* Divex – Scottish provider of diving equipment and related services.
* Diviac – Online booking site for diving holidays
* Diving accident – Accident occurring while diving underwater
* Diving accident investigation – Forensic investigation into causes of reportable incidents
* Diving activities – Things people do while diving underwater
* Diving air compressor, also known as diving compressor – Machine used to compress breathing air for use by underwater divers
* Diving air compressor operator – Person who operates a diving air compressor
* Diving air filter – Device to purify compressed breathing air
* Diving air pump – Manually powered surface air supply for divers
* Diving attendant – Member of a dive team responsible for assisting the diver
* Diving at Work Regulations 1997 – UK legislation regulating all aspects of professional diving
* Diving basket – Platform for lowering and lifting a diver through the water
* Diving bell – Chamber for transporting divers vertically through the water
* Diving bell cross-haul system, also known as diving bell cross-hauling system – Cables to move a bell laterally under the water
* Diving bell deployment – Deployment of a modern diving bell
* Diving boat – Boat used for the support of scuba diving operations
* Diving buddy – Diver who dives as one of a buddy pair
* Diving certification – Evidence of having been trained to a standard
* Diving chamber – Hyperbaric pressure vessel for human occupation used in diving operations
* Diving chamber operation – Operation of a hyperbaric chamber in support of underwater diving
* Diving compass – Compass intended for diver navigation
* Diving contractor – The legal persona responsible for professional diving operations for a client
* Diving control board – Group with responsibility for all scientific diving work done by an American organisation
* Diving cylinder – Container to supply high pressure breathing gas for divers
* Diving destination – Places where recreational divers go on vacation
* Diving Diseases Research Centre (DDRC) – British hyperbaric medical organisation
* Diving disorders – Physiological disorders resulting from underwater diving
* Diving emergency – Situation that endangers the life or health of a diver
* Diving environment – Characteristics of the environment in which underwater diving takes place
* Diving equipment – Equipment used to facilitate underwater diving
* Diving Equipment and Marketing Association (DEMA) – International trade association for the recreational diving equipment industry
* Diving equipment maintenance and testing – Ensuring that the equipment is safe to use
* Diving equipment technician – Person who maintains, repairs and tests diving and support equipment
* Diving fatalities – Deaths associated with underwater diving
* Diving flag – Flag signal indicating divers are in the water nearby
* Diving gas analysis – Measuring the components in a breathing gas blend
* Diving glove – Hand protection worn while driving
* Diving half-mask – Mask covering the nose and eyes of an underwater diver
* Diving hand signals – A form of sign system used to communicate underwater
* Diving harness – Item fastened around a diver which allows the diver to be lifted
* Diving hazards – Agents and situations that pose a threat to the underwater diver
* Diving heavy – Underwater diving while intentionally negatively buoyant
* Diving helmet – Rigid head enclosure for underwater diving
* Diving incident and accident investigation – Forensic investigation of underwater diving accidents
* Diving in cold water – Diving in water where heat loss is a serious problem
* Diving in cool water – Conditions where heat loss is easily managed
* Diving in freezing water – Diving in water temperatures near freezing point
* Diving in hot water – Diving in conditions where active cooling is necessary
* Diving instructor – Person who trains and assesses underwater divers
* Diving Instructor – Person who trains and assesses underwater divers
* Diving instrument console – Mounting for a group of scuba diving instruments
* Diving in warm water – Diving in conditions where no thermal protection is needed
* Diving jackstay – Form of guideline laid between two points to guide the diver
* Diving jargon – Definitions of jargon, diver slang and acronyms used in underwater diving
* Diving ladder – Ladder to facilitate egress from the water by divers
* Diving law – Laws directly affecting diving activities
* Diving legislation – Legislation directly affecting diving activity
* Diving light – Portable light source for use underwater
* Diving line signals – Standard signals coded in the form of tugs on the diver's lifeline
* Diving locations – Places that divers go to enjoy the underwater environment
* Diving logbook – Record of diving history of an underwater diver
* Diving mask – Watertight air-filled face cover with view-ports for improving underwater vision
* Diving mask clearing – Removing water from a flooded diving mask underwater
* Diving Medical Advisory Council (DMAC) – Independent organisation of diving medical specialists from Northern Europe
* Diving medical examination – Assessment of medical fitness to dive
* Diving medical examiner – A medical practitioner registered to assess medical fitness to dive
* Diving Medical Examiner – A medical practitioner registered to assess medical fitness to dive
* Diving medical practitioner – Specialist in diagnosis, treatment and prevention of disorders caused by underwater diving
* Diving Medical Practitioner – Specialist in diving medicine
* Diving medical technician – Person trained in advanced first aid for divers
* Diving Medical Technician – Person trained in advanced first aid for divers
* Diving medicine – Diagnosis, treatment and prevention of disorders caused by underwater diving
* Diving Medicine Physician – Doctor registered as competent to manage diving accidents
* Diving mode – The conceptual methods of underwater diving
* Diving operation – Underwater dive and support activities to achieve a specific goal
* Diving operations record – Documentation recording a professional dive
* Diving physics – Aspects of physics which affect the underwater diver
* Diving physiology – Influences of the underwater environment on the physiology of human divers
* Diving platform (scuba) – Low freeboard platform on a dive boat to give divers easy access to the water
* Diving procedures – Standardised methods of doing things that are known to work effectively and acceptably safely
* Diving project – The overall diving job by a diving contractor under a specific contract
* Diving rebreather – Closed or semi-closed circuit scuba
* Diving reflex – The physiological responses to immersion of air-breathing vertebrates
* Diving regulations – Stipulations of the delegated legislation regarding the practice of underwater diving
* Diving regulator – Mechanism that controls the pressure of a breathing gas supply for diving
* Diving regulator clearing – Removal of water from a scuba regulator mouthpiece
* Diving regulator malfunction – Failure modes of breathing gas control valves for underwater diving
* Diving response – The physiological responses to immersion of air-breathing vertebrates
* Diving safety – Risk management of underwater diving activities
* Diving safety equipment – Equipment used to facilitate underwater diving safety
* Diving safety harness – A harness by which the diver can safely be lifted
* Diving safety officer – Administrator of a US university's research diving safety program
* Diving school – Establishment for training and assessing underwater divers
* Diving Science and Technology (DSAT) – PADI affiliate and developer of recreational decompression planning tools
* Diving shot, also known as shot line – Substantial weighted near-vertical line with buoy
* Diving signal – Signals made by divers for communication
* Diving skins – Suit worn to protect the skin from jellyfish stings, abrasion and sunburn
* Diving spread – The topside base for commercial diving operations
* Diving stage – Platform on which a diver is transported vertically through the water
* Diving stage deployment – Launch and recovery of a diving stage
* Diving suit – Garment or device designed to protect a diver from the underwater environment
* Diving suit hood – Protective headgear worn by underwater diver
* Diving superintendent – A management position responsible for diving operations
* Diving supervisor – Professional diving team leader responsible for safety
* Diving support equipment – Equipment used in the support of an underwater diving operation
* Diving support personnel – People involved in the support of diving operations
* Diving support vessel – Ship used as a floating base for professional diving projects
* Diving systems technician – A competent person who maintains and repairs diving life-support equipment
* Diving team – Group of people working together to enhance dive safety and achieve a task
* Diving team tools and equipment – Equipmemt shared by the members of a diving team
* Diving terminology – Definitions of technical terms, jargon, diver slang and acronyms used in underwater diving
* Diving terms – Definitions of technical terms, jargon, diver slang and acronyms used in underwater diving
* Diving theory – The knowledge required for safe diving
* Diving tourism – Tourism focused on recreational diving activities
* Diving tourism industry – Industry based on recreational diver travel
* Diving Unlimited International – American manufacturer of dry suits and other diving equipment
* Diving watch – Watch designed for underwater diving
* Diving weight – Ballast carried by a diver to counteract buoyancy or adjust trim
* Diving weight harness – Diver ballast system supported by straps over the shoulders
* Diving weighting system – Ballast carried to counteract buoyancy

### Do

Section contents: Top of section, Da–Dd, De, Di, Do, Dr, Ds, Du–Dw, Dy
* Doing It Right (scuba diving) (DIR) – Technical diving safety philosophy
* Donald Duck effect – Type of speech distortion caused by the breathing gas
* Donald, Kenneth William – British expert on underwater and exercise physiology.
* Doppler bubble detection, also known as ultrasonic bubble detection – Detection of vascular bubbles by ultrasound
* Downline (diving) – Rope from the surface to an underwater workplace
* Downstream scuba manifold – Component used to functionally connect scuba cylinders
* Downstream valve – Valve which is opened along the pressure differential

### Dr

Section contents: Top of section, Da–Dd, De, Di, Do, Dr, Ds, Du–Dw, Dy
* Dräger (company) – German manufacturer of breathing equipment
* Dräger Atlantis – Semi-closed circuit recreational diving rebreather
* Dräger DM20 oxygen rebreather system – Oxygen rebreather system for copper helmet
* Dräger DM40 mixed gas rebreather system – Nitrox rebreather system for copper helmet
* Dräger Dolphin – Semi-closed circuit recreational diving rebreather
* Dräger Modell 1915 Bubikopf helmet – Copper helmet for rebreather systems
* Dräger Ray – Semi-closed circuit diving rebreather
* Draining the rebreather loop – Removing water from the breathing circuit
* Drass-Galeazzi – Italian manufacturer of lightweight diving helmets
* DRDC Toronto – Major military research station in Canada
* Drift diving – Scuba diving where the diver is intentionally transported by the water flow
* Drifting surface buoy – Oceanographic instrument package floating at the surface transported by current
* Drill Master diving accident – Fatal diving bell accident off Norway in 1974
* Drop tank (scuba) – Scuba set placed along the guideline on a cave dive for later use
* Drowning – Respiratory impairment caused by submersion in liquid
* Dry bell – Hyperbaric chamber for transporting diversvertically through the water
* Dry Combat Submersible – Midget submarine project
* Dry suit – Watertight clothing that seals the wearer from cold and hazardous liquids
* Dry suit blowup – Over-inflation of a dry suit causing uncontrolled ascent
* Dry suit diver – Certification for diving in a dry suit
* Dry suit inflation cylinder – Diving cylinder dedicated for suit inflation gas
* Dry suit inflation hose – Low pressure inflation gas supply
* Dry suit inflation valve – Manual valve to admit low pressure gas into a diving dry suit
* Dry suit inflator – Equipment to add air inside a diver's dry suit
* Dry suit inversion and blowup – Dangerous malfunction or misuse of diving dry suit
* Dry suit squeeze – Compression of the dry suit at depth which can pinch the skin and restrict motion

### Ds

Section contents: Top of section, Da–Dd, De, Di, Do, Dr, Ds, Du–Dw, Dy
* DSRV-2 Avalon – Mystic-class deep-submergence rescue vehicle
* DSV-5 Nemo – Submersible used by the United States Navy
* DSV Alvin – Crewed deep-ocean research submersible
* DSV Bakunawa – Crewed full ocean depth rated submersible
* DSV Fendouzhe – Chinese deep submergence vehicle
* DSV Limiting Factor – Crewed full ocean depth rated submersible
* DSV Sea Cliff – US Navy crewed deep-ocean research submersible
* DSV Shinkai – Crewed research submersible
* DSV Shinkai 2000 – Japanese crewed research submersible
* DSV Shinkai 6500 – Japanese crewed research submersible
* DSV Turtle – US Navy crewed deep-ocean research submersible

### Du–Dw

Section contents: Top of section, Da–Dd, De, Di, Do, Dr, Ds, Du–Dw, Dy
* Dual bladder buoyancy compensator – Scuba diving buoyancy compensator with redundant air bag
* Duckbill valve – Type of check valve
* Dump valve (diving) – Pressure relief and manual vent on diving buoyancy compensator
* Dutch Underwater Sports Association – Dutch governing body for underwater sports
* Duty of care – Type of legal obligation
* Dwell time (filtration) – Time that fluid spends passing through active filter medium

### Dy

Section contents: Top of section, Da–Dd, De, Di, Do, Dr, Ds, Du–Dw, Dy
* Dynamic apnea – Freediving disciplines where the diver swims horizontally under water
* Dynamic compression of the airways, also known as dynamic airway compression – Mechanism reducing lung airway section area during forced expiration
* Dynamic positioning – Automatic ship station- and heading-holding systems
* Dynamically positioned vessel (DPV) – Ship with automatic station- and heading-holding systems
* Dynamically Positioned Vessel Owners Association (DPVOA) – Precursor to International Marine Contractors Association
* Dysbaric osteonecrosis – Ischemic bone disease caused by decompression bubbles
* Dysbarism – Medical conditions resulting from changes in ambient pressure

## E

| 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, Ea–Ek, El, Em, En–Ep, Eq–Er, Es, Eu–Ev, Ex

### Ea–Ek

* Ear clearing, also known as ear equalisation – Equalising of pressure in the middle ears
* Ebullism – Formation of vapour bubbles in bodily fluids due to reduced environmental pressure
* Ecological impact of recreational diving – Effects of scuba diving on the underwater environment
* Eelume – Autonomous underwater vehicle being developed by Eelume AS
* Effects of drugs on fitness to dive – Known side-effects and contraindications of drugs commonly used by divers
* Ekman transport – Net transport of surface water perpendicular to wind direction

### El

Section contents: Top of section, Ea–Ek, El, Em, En–Ep, Eq–Er, Es, Eu–Ev, Ex
* Electro-galvanic oxygen sensor – Electrochemical device for measuring oxygen partial pressure
* Electronically controlled closed circuit rebreather – Underwater breathing apparatus with automatic gas composition control

### Em

Section contents: Top of section, Ea–Ek, El, Em, En–Ep, Eq–Er, Es, Eu–Ev, Ex
* Emergency air sharing, also known as emergency gas sharing, and emergency breathing gas sharing – Supply of breathing air from one scuba diver to another
* Emergency ascent – An ascent to the surface by a diver in an emergency
* Emergency breathing gas sharing – Supply of breathing gas from one scuba diver to another
* Emergency buoyant ascent – Emergency procedure in underwater diving
* Emergency closed bell procedures, also known as closed bell emergency procedures – Standard procedures for use in common surface-supplied closed bell diving emergencies
* Emergency ditching of diving weights – Emergency removal of diving weights to increase buoyancy
* Emergency gas sharing – Supply of breathing gas from one scuba diver to another
* Emergency gas supply – Alternative independent breathing gas supply carried by a diver
* Emergency procedure – Plan of action to deal with an emergency
* Emergency Response Diving International (ERDI) – American organisation for training and certification of emergency response divers
* Emergency response plan – Action to be taken in specific emergencies
* Emergency swimming ascent (ESA) – Emergency procedure used by scuba divers
* Emergency tethered ascent, also known as buoyant tethered ascent – Positive buoyancy emergency ascent using a reel upline
* Emergency wet bell procedures, also known as wet bell emergency procedures – Standard procedures for use in common surface-supplied wet bell diving emergencies

### En–Ep

Section contents: Top of section, Ea–Ek, El, Em, En–Ep, Eq–Er, Es, Eu–Ev, Ex
* EN 1972:1997 – European standard for design and manufacture of snorkels
* Engineer diver (disambiguation)
* Engineering controls – Hazard controls that are physical changes to the workplace
* Engineering redundancy – Duplication of critical components to increase reliability of a system
* Entanglement (hazard) – Entrapment by lines or nets
* Entry level diver training – Minimum standard for diver trainingu in a given context
* Entry level recreational diver training – Minimum standard for entry level recreational scuba diver training
* Environmental effects of scuba diving – Effects of recreational scuba diving on the underwater environment
* Environmental impact of recreational diving – Effects of scuba diving on the underwater environment
* Environmental impact of scuba diving – Effects of recreational scuba diving on the underwater environment
* Épaulard – French remotely operated underwater vehicle of the Ifremer

### Eq–Er

Section contents: Top of section, Ea–Ek, El, Em, En–Ep, Eq–Er, Es, Eu–Ev, Ex
* Equalising the ears – Balancing pressure in the middle ears with ambient pressure
* Equivalent air depth – Method of comparing decompression requirements for air and a given nitrox mix
* Equivalent narcotic depth – Method for comparing the narcotic effects of a mixed diving gas with air
* Ergonomics of diving equipment – Interaction between diving equipment and the diver

### Es

Section contents: Top of section, Ea–Ek, El, Em, En–Ep, Eq–Er, Es, Eu–Ev, Ex
* Escape breathing apparatus – Self contained breathing apparatus providing gas to escape from a hazardous environment
* Escape trunk – Ambient pressure escape system for submarines

### Eu–Ev

Section contents: Top of section, Ea–Ek, El, Em, En–Ep, Eq–Er, Es, Eu–Ev, Ex
* EUF Certification International – Independent body for global verification of rebreather training agencies
* Eurocylinder Systems AG, also known as Eurocylinder – German manufacturer of seamless steel pressure cylinders for gas
* European Diving Technology Committee (EDTC) – International organisation for improving professional diver safety
* European Scientific Diver – Qualification for scientific divers
* European Scientific Diving Panel – A panel of the European Network of Marine Research Institutes and Stations
* European Underwater and Baromedical Society (EUBS) – Source of information for diving and hyperbaric medicine
* European Underwater Federation (EUF) – Umbrella organisation representing scuba diver training organisations in Europe
* Evacuation plan – Plan for removal of personnel from a high risk area or a developing incident to a safer place

### Ex

Section contents: Top of section, Ea–Ek, El, Em, En–Ep, Eq–Er, Es, Eu–Ev, Ex
* Exceptional Exposure Tables – Air diving tables for unusually long and deep dives
* Excursion from storage depth – Change of depth from the nominal depth in the saturation habitat
* Excursion umbilical – A diver's umbilical supplied from a bell gas panel
* Exercise Paddington Diamond – Joint Bolivian-British-Swiss scuba diving expedition to Lake Titicaca
* Expanding square search – Search pattern expanding stepwise outward from datum
* Explorer AUV – Autonomous underwater vehicle from People's Republic of China
* Exponential–Linear model – Decompression model based on exponential gas uptake and linear elimination
* Explosive ordnance disposal (United States Navy) – US Navy personnel who render safe or detonate unexploded ordnance
* Exposure assessment – Measuring toxic or environment exposure
* Extended range surface-supplied air diver – Surface-supplied offshore air diving to 50 msw using a wet bell and hot water suit
* External dead space – Space in breating apparatus in which the breathing gas flows in both directions
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