Index of underwater diving: T–Z

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:

T

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

Subsection: Ta, Te, Th, Ti, To, Tr, Tu, Tw, Ty

T1200 Trenching Unit – Remotely operated seabed trenching unit

Ta

Tactical diver – Military scuba diver
Tactical Divers Group – Special operations force of the Argentine Navy.
Taifib – Indonesian amphibious reconnaissance unit
Talus cave – Type of cave
Tank weight – Ballast weight attached to a scuba cylinder
Taravana – Decompression sickness after breath-hold diving
Task loading – Relationship between operator capacity and the accumulated activities that must be done

Te

Teaching method – Principles and methods used by teachers to enable student learning
Team redundancy – System for sharing backup equipment and skill diversity
Technical diver training – Processes to develop skills and knowledge to dive safely for technical diving
Technical diving – Extended scope recreational diving
Technical diving instructor – Person certified to train recreational divers in technical disciplines
Technical Diving International (TDI) – Technical diver training and certification agency
Technical Extended Range (TXR) – Recreational scuba and freediving training and certification agency
Tektite habitat – Undersea laboratory and experimental habitat
Temperate reef – Hard benthic substrate and ecosystems in cool to cold water in middle latitudes
Temperature – Physical quantity of hot and cold
Tension-leg platform – Type of offshore platform used in production of oil or gas
Tesei, Teseo – Italian naval officer and pioneering military diver
Test of pressure – Diagnostic technique to identify decompression sickness
Testing and inspection of diving cylinders – Periodical inspection and testing to revalidate fitness for service
Tethered ascent, also known as emergency tethered ascent, buoyant tethered ascent – Positive buoyancy emergency ascent using a reel upline (for CMAS Self-Reliant Diver)
Texas Finswimming Association – Official governing body for competitive and recreational finswimming in Texas

Th

Thalmann algorithm – Mathematical model for diver decompression
Thalmann, Edward D. – American hyperbaric medicine specialist and decompression researcher
Tham Luang cave rescue – 2018 international rescue in Thailand
The Darkness Beckons – History of UK cave diving by Martyn Farr
The Last Dive – Non-fiction book by Bernie Chowdhury about a double wreck diving fatality
Therapeutic decompression tables – Planned hyperbaric exposure profiles to treat decompression sickness
Therapeutic recompression – Recompression to reduce symptoms of decompression illness
Thermal balance of the underwater diver, also known as thermal balance of divers – Conditions in which the temperature of a diver can remain stable
Thermal balance of the saturation diver – Maintaining body heat in the saturation diver
Thermal comfort zone (TCZ) – Range of temperature and humidity comfortable for people
Thermal neutral zone (TNZ), also known as thermoneutral zone – Minimal metabolic regulation to retain ambient core body temperature
Thermal undersuit – Insulating undergarments for use with a dry suit
Thermocline – Distinct layer of temperature change in a body of water
Thermodynamic model of decompression, also known as Thermodynamic decompression model – Early model in which decompression is controlled by volume of gas bubbles forming in tissues
Theseus (AUV) – Large autonomous underwater vehicle for laying fibre-optic cable
The Shaft (sinkhole) – Karst feature in South Australia
The Silent World – 1956 French documentary film co-directed by Jacques Cousteau and Louis Malle
The Silent World: A Story of Undersea Discovery and Adventure – Book by Jacques-Yves Cousteau and Frédéric Dumas
Three bolt equipment – Standard diving dress using three bolts to clamp the helmet bonnet to the corselet
Three Star Diver – Fully trained and experienced recreational diver
Through-water communications – Wireless diver voice communications equipment

Ti

Tidal race – Fast-moving tidal flow passing through a constriction, forming waves, eddies and strong currents
Tide – Rise and fall of the sea level under astronomical gravitational influences
Tillman, Albert – American educator and underwater diver
Timeline of diving technology, also known as Timeline of underwater diving technology – Chronological list of notable events in the history of underwater diving equipment
Time to surface (TTS) – Estimated ascent and decompression time from a given point on a dive profile
Tissue (biology) – Group of similar cells performing a specific function
Tissue gas loading – Amount of gas dissolved in a tissue
Tissue slab decompression model – A diffusion limited series tissue decompression model
Tissue slab diffusion model – Diffusion limited series tissue decompression model

To

Toggle bag (concrete placement) – Method of concrete placement suitable for underwater use
Torricellian chamber – Type of cave chamber
Total Nitrogen Time (TNT) – Equivalent pressure exposure estimate for a repetitive dive
Touboulic, Pierre-Marie – French engineer, inventor and writer
Tourism on the Great Barrier Reef – Service industry in Australia involving recreational diving
Towboard – Underwater survey equipment used to tow a diver

Tr

Training dive sites – Underwater environments selected as suitable for diving skills training
Transfer under pressure (TUP) – Moving between pressurised vessels without decompression
Transfer under pressure diving – Surface oriented diving from a closed bell and a chamber for decompression
Travel gas – Gas breathed during the descent part of a dive
Tremie – Equipment for underwater concrete placement
Trial diving – Introductory scuba diving experience
Tribonucleation – Mechanism for creation of microbubbles
Trieste II – US Navy's second bathyscaphe
Triger, Jacques – French geologist who invented the pressurised caisson (1801–1867)
Trim weights (diving) – Diving weights distributed primarily to improve trim
Trimix blender – Person competent to blend trimix breathing gases for scuba diving
Trimix (breathing gas) – Breathing gas consisting of oxygen, helium and nitrogen
Trimix Scuba Association (TSA) – Recreational technical scuba training and certification agency
Trongle – Device used on submarines to help swimmers to locate a submerged submarine
Tropical coral reef – Reefs built by warm-water coral species
Try-dive – Supervised diving experience to try out diving or equipment

Tu

Tubesuit – Active heat transfer undergarment
Turbidity – Cloudiness of a fluid
Turkish Underwater Sports Federation (TSSF), also known as Türkiye Sualtı Sporları Federasyonu – Turkish national governing body for underwater sport and lifesaving
Turn pressure – Gas pressure at which the divers start the return from a dive

Tw

Twin bladder buoyancy compensator – Scuba diving buoyancy compensator with redundant air bag
Twin-hose regulator – Scuba regulator with two ambient pressure hoses to the mouthpiece

Ty

Type 1 wet bell – Open diving bell without onboard gas panel
Type 2 wet bell – Diving bell with onboard gas panel
Type 904 dive tender – Chinese class of naval diving support vessel

U

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

Subsection: Ul–Um, Un, Up–Ur, Us, Uw

Ul–Um

Ultra deep air diving – Scuba diving on air to very dangerous depths
Umbilical cable – A cable and/or hose bundle which supplies required consumables to a remote user
Umbilical management – Safe handling of the diver's umbilical
Umbilical tending – Management of the supply end of the diver's umbilical

Un

Uncontrolled buoyant ascent – Type of diving accident
Uncontrolled decompression – Unplanned drop in the pressure of a sealed system
Undersea and Hyperbaric Medical Society (UHMS) – US based organisation for research and education in hyperbaric physiology and medicine.
Undersea Medical Society – Original name of Undersea and Hyperbaric Medical Society
The Undersea World of Jacques Cousteau – Documentary television series about underwater marine life
Undersuit – Clothing worn under a protective suit
Undertow (water waves) – Return flow below (nearshore) water waves.
Underwater – Aquatic or submarine environment
Underwater acoustic communication – Wireless technique of sending and receiving messages through water
Underwater acoustic positioning system – System for tracking and navigation of underwater vehicles or divers using acoustic signals
Underwater acoustics – Study of the propagation of sound in water
Underwater archaeology – Archaeological techniques practiced at underwater sites
Underwater archaeology techniques – Methodology used in underwater archaeology
Underwater art – Works that are designed for or performed in an underwater environment
Underwater Bike Race – Annual charity event in North Carolina
Underwater blackout syndrome – Loss of consciousness caused by cerebral hypoxia towards the end of a breath-hold dive
Underwater breathing apparatus – Equipment which provides breathing gas to an underwater diver
Underwater camera housing – Water and pressure resistant container for camera
Underwater citizen science – The organised collection of underwater data for scientific purposes by volunteers
Underwater computer vision – Subfield of computer vision
Underwater concrete placement – Positioning freshly mixed concrete at an underwater location where it is to set
Underwater construction – Industrial construction in an underwater environment
Underwater Construction Teams – Navy construction battalion underwater construction units
Underwater cutting and welding – Metalworking techniques used by underwater divers
Underwater cycling – Stunt in which a bicycle is ridden under water
Underwater Defence (Turkish Armed Forces) – Special operations unit of the Turkish Navy
Underwater demolition – The deliberate destruction or neutralization of man-made or natural underwater obstacles
Underwater Demolition Command – Special warfare unit of the Greek Navy
Underwater Demolition Team – US Navy special operations group
Underwater dive – Instance of underwater diving activity
Underwater diver – Person who descends below the surface to interact with the environment
Underwater diver training – Processes by which people develop the skills and knowledge to dive safely underwater
Underwater divers – People who participate in underwater diving
Underwater diving – Descending below the surface of the water to interact with the environment
Underwater diving emergency – Situation that endangers the life or health of a diver
Underwater diving environment – The underwater environment to which a diver may be exposed
Underwater diving equipment – Equipment used to facilitate underwater diving
Underwater diving hazards – Agents and situations that pose a threat to the underwater diver
Underwater diving on Guam – Recreational diving tourism destination
Underwater diving safety – Safety and risk management in underwater diving
Underwater diving terminology, also known as Underwater diving terms – Definitions of technical terms, jargon, diver slang and acronyms used in underwater diving
Underwater domain awareness – Underwater component of maritime domain awareness
Underwater environment – Aquatic or submarine environment
Underwater exploration – Investigating or traveling around underwater for the purpose of discovery
Underwater Explorers Club – British diving club, now defunct
Underwater firearm – Firearms that can be effectively fired underwater
Underwater football – Underwater team sport using snorkeling equipment and an American football
Underwater glider – Type of autonomous underwater vehicle
Underwater habitat – Human habitable underwater enclosure filled with breathable gas
Underwater hockey – Underwater sport of pushing a puck into the opposing goal
Underwater hockey in Australia
Underwater hockey in Turkey
Underwater Hockey Wales – Welsh underwater hockey association
Underwater Hockey World Championships – International event for the sport of Underwater Hockey
Underwater ice hockey – Freediving variant of ice hockey played upside-down under the ice
Underwater inspection – Examination of underwater structure and equipment to assess condition
Underwater mining – Any mining activity done underwater
Underwater music – Music composed to be performed or heard underwater
Underwater navigator – Diver competent to navigate in open water by compass or pilotage
Underwater Offence (Turkish Armed Forces) – Special operations Forces of the Turkish Navy
Underwater orienteering – Underwater compass navigation and speed competition on scuba.
Underwater Orienteering World Championships – International sporting competition
Underwater painting – Technique of painting underwater
Underwater photography – Genre of photography
Underwater photography (sport) – Competitive underwater digital photography on scuba
Underwater Photography World Championships – International event for the sport of underwater photography
Underwater pilotage – Diver navigation using natural features
Underwater Port Security System – Defense against hostile swimmer incursions
Underwater rescue – Rescue of persons trapped underwater
Underwater rifle – A man-portable, long-barreled firearm which can be fired effectively underwater
Underwater rugby – Underwater team sport
Underwater rugby in Australia – Team breathhold underwater sport
Underwater rugby in Colombia – Regional sporting activity
Underwater rugby in the United States – Watersport played on breathhold
Underwater Rugby World Championships – International sporting competition
Underwater sculpture – Sculpture made for underwater display
Underwater search and recovery – Locating and recovering underwater objects
Underwater searches – Techniques for finding underwater targets
Underwater Society of America (USOA) – American national representative organization for underwater sport.
Underwater sports – Competitive underwater recreational activities
Underwater sports at the 2013 Bolivarian Games – Finswimming, free-diving and spearfishing events at San Lorenzo island
Underwater survey – Inspection or measurement in or of an underwater environment
Underwater surveying – Inspection or measurement in or of an underwater environment
Underwater target shooting – Breathhold underwater sport of target shooting with a speargun in a swimming pool.
Underwater tender – Diver who attends to the umbilical of another diver while underwater
Underwater tending point – Place where the diver's umbilical is restrained or controlled
Underwater vehicle – Vehicle intended to operate underwater
Underwater videographer – Diver trained in the use of video recorders underwater
Underwater videography – Electronic underwater photography concerned with capturing moving images
Underwater visibility – Distance at which an object can be seen through water
Underwater vision – The ability to see objects underwater
Underwater warfare – One of the three operational areas of naval warfare
Underwater work – Work done underwater during diving operations
Underwater wrestling (disambiguation)
Under way – State of a vessel free to move through the water
UNESCO Code of Practice for Scientific Diving – Principles for the safe practice of diving for science
United Diving Instructors (UDI) – Recreational diver training and certification agency
United States Marine Corps Combatant Diver Course – Military diver training for the US Marines
United States Marine Corps Force Reconnaissance – USMC deep reconnaissance unit
United States Marine Corps Reconnaissance Battalions – Reconnaissance assets of Marine Air-Ground Task Force
United States military divers – Underwater divers employed by the US armed forces
United States Navy Experimental Diving Unit (NEDU) – The primary source of diving and hyperbaric operational guidance for the US Navy
United States Navy SEALs – U.S. Navy special operations force
United States Navy SEAL selection and training – Special forces unit policy and procedures
Universal Referral Program – System to complete recreational scuba training with another instructor
Unmanned diving – Underwater diving by autonomous or remotely operated vehicles

Up–Ur

Upstream scuba manifold – Manifold connecting cylinders upstream of the valve
Upstream valve – Valve which is opened against the pressure differential
Upwelling – Oceanographic phenomenon of wind-driven motion of ocean water
URF (Swedish Navy) – Swedish submarine rescue vehicle

Us

U.S. Divers – Manufacterer of scuba diving equipment
User respiratory interface – Facepiece of a breathing apparatus
US Navy decompression models and tables
U.S. Navy Diving Manual (USNDM), also known as United States Navy Diving Manual, or US Navy Diving Manual – Training and operations handbook
U.S. Navy Experimental Diving Unit (USNEDU, NEDU) – The primary source of diving and hyperbaric operational guidance for the US Navy

Uw

Uwatec – Manufacturer of diving equipment

V

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

Subsection: Va, Ve, Vi, Vo

Va

Valsalva device – Pad in a helmet or mask used to block the nose to assist in ear clearing
Valsalva maneuver – Technique for equalising pressure in the middle ears
Valve cracking pressure – Pressure difference needed to open a valve
Variable weight apnea – Deep freediving using a weighted sled for descent, pulling along the depth rope for ascent
Variable weight apnea without fins – Competitive freediving discipline
Variable-buoyancy pressure vessel – Type of rigid buoyancy control device
Variable-buoyancy propulsion – Use of a buoyancy engine to provide propulsion
Variable density buoyancy compensator – Equipment for controlling the buoyancy of a diver or submersible
Variable volume buoyancy compensator – Equipment for controlling the buoyancy of a diver
Varying Permeability Model – Decompression model and algorithm based on bubble physics
Vasa (ship) – 17th-century Swedish warship

Ve

Venting the rebreather loop, also known as venting the loop – Intentionally releasing gas from the breathing circuit}
Venture One diving accident – Saturation diving fatality in the North Sea in 1977
Vertical Blue – Freediving competition in The Bahamas at Dean's Blue Hole
Vertigo – Type of dizziness where a person has the sensation of moving or surrounding objects moving

Vi

VideoRay UROVs – Series of inspection class remotely operated underwater vehicles
Viewport (diving) – Transparent part of a helmet, submersible, or diving chamber
Vintage scuba – Early model scuba equipment and the ongoing activity of diving with it

Vo

Volumetric gas fraction – Dimensionless quantity
Voyage to the Edge of the World – 1976 French nature documentary
VVAL 18 – Mathematical model for diver decompression

W

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

Subsection: Wa, We, Wi, Wo, Wr

Wa

Waage Drill II diving accident – Fatal saturation diving accident in the North Sea in 1975
Wall diving – Underwater diving alongside a near vertical face
WASP atmospheric diving system – Type of armoured diving suit without leg articulation
Water clarity – How deeply visible light penetrates through water
Water polo cap – Headgear used in water polo and a number of underwater sports
Waterproof digital camera – Digital still camera with inherently waterproof casing
Water safety – Human safety in the vicinity of bodies of water
Water separator – Device to remove condensed water from compressed air
Water surface searches – Procedures to find objects or persons lost at the surface of a body of water
Watertight zipper – Zipper closure which prevents water leakage when closed
Waves and shallow water – Effect of shallow water on a surface gravity wave
Wave shoaling – Effect by which surface waves entering shallower water change in wave height

We

Weight – Force on a mass due to gravity
Weight belt – Ballast carried to counteract buoyancy
Weighted boots (diving) – Shoes with heavy metal soles used as part of a diver's weights
Weighted shoes (diving) – Shoes with heavy metal soles used as part of a diver's weights
Weight harness – Webbing system to support diver ballast weights
Weight pocket – Container on diving equipment to hold ballast
Welfreighter – British midget submarine of the Second World War
Wells, John Morgan – Physiologist, aquanaut and researcher (1940–2017)
Welman submarine – Second World War one-man British midget submarine
Welsh Association of Sub Aqua Clubs – Welsh national governing body for underwater sport and recreational diving
Wet Nellie – 1976 car-shaped submarine from the James Bond film The Spy Who Loved Me
Wet sub – Ambient pressure diver propulsion vehicle
Wetsuit – Garment for thermal insulation from water
Wetsuit boots – Foam neoprene footwear for watersports
Wetsuit buoyancy – Upwards forece generated by the volume of an immersed wetsuit
Wetsuit buoyancy loss – Temporary reduction of volume due to compression at depth

Wi

Wildrake diving accident – Fatal offshore diving accident in Scotland, 1979
Willful ignorance – Strategy for attempting to avoid liability
Willful violation – Deliberate or negligent violation of workplace rules and policies
Wind generated current – Flow in a body of water generated by wind friction on its surface
Wind wave – Surface waves generated by wind on open water

Wo

Women Divers Hall of Fame – International honor society.
Woodville Karst Plain Project (WKPP) – Project and organization to map the underwater cave systems of the Woodville Karst Plain
Work of breathing (WOB) – Energy expended to inhale and exhale a breathing gas
Working diver – The person who is intended to do the underwater work during a professional dive
Workplace health surveillance – Ongoing surveillance of workers' health
World Recreational Scuba Training Council (WRSTC) – Scuba diving standards body
World Without Sun – 1964 film by Jacques Cousteau

Wr

Wreck Alley – Area off California with several wrecks sunk as artificial reefs
Wreck diving – Recreational diving on wrecks
Wreck penetration diving – Diving inside a sunken shipwreck

X

Y

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

YMCA SCUBA Program – Defunct recreational diver training and certification agency
Yoke connector – Clamp to connect scuba regulator to cylinder valve
Yoke (diving helmet) – Component to prevent accidental removal of a diving helmet

Z

Α–Ω

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Δ-P (hazard) – Underwater hazard due to strong localised pressure differential

T

Ta

Te

Th

Ti

To

Tr

Tu

Tw

Ty

U

Ul–Um

Un

Up–Ur

Us

Uw

V

Va

Ve

Vi

Vo

W

Wa

We

Wi

Wo

Wr

X

Y

Z

Α–Ω

See also