# Index of underwater diving: S

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

## S

| 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, Sa–Sb, Sc–Sd, Se, Sh, Si–Sj, Sk, Sl, Sm, Sn, So, Sp–Sr, St, Su, Sw, Sy

### Sa–Sb

* Safety culture – Risk-averse attitudes
* Safety data sheet, also known as material safety data sheet (MSDS) – Sheet listing work-related hazards of a product or substance
* Safety diver – Support diver for a freediver
* Safety sausage – Inflatable buoy used by a diver at the surface to indicate position to the dive boat
* Safety stop – Optional decompression stop to reduce decompression stress
* Salt spray aspiration – Inhalation of salt water droplets
* Salt water aspiration syndrome – Diving disorder caused by inhaling small quantities of salt water
* Salvage diving – Diving work associated with the recovery of vehicles, cargo and structures
* Salvage of the SS Egypt's gold – Recovery of bullion from wreck using an atmospheric pressure observation bell
* Salvage operations on HMS Royal George, also known as Salvage work on the wreck of HMS Royal George – Early salvage operations using bells and surface supplied divers
* Sappers Divers Group – Portuguese Navy's diving unit
* Saturation diver – Diver registered as competent for saturation diving
* Saturation diving – Diving mode and decompression technique
* Saturation diving skills – Surface-supplied diving skills specific to saturation operations
* Saturation diving system – Facility for supporting saturation diving projects
* Saturation diving team – Personnel supporting a saturation diving operation
* Saturation spread – The topside base for saturation diving operations
* Saturation system – Diving decompression system
* Save Ontario Shipwrecks (SOS) – A provincial heritage NGO in Ontario, Canada
* Savoie, Joe – Diver and inventor of diving helmets
* Saw-tooth dive profile – Dive with several ascents and descents
* S-BRUV – Stereoscopic baited remote underwater video

### Sc–Sd

Section contents: Top of section, Sa–Sb, Sc–Sd, Se, Sh, Si–Sj, Sk, Sl, Sm, Sn, So, Sp–Sr, St, Su, Sw, Sy
* A. Schräder's Son – US Manufacturer of diving equipment
* Science of underwater diving – Scientific concepts that are closely associated with underwater diving
* Scientific committee of CMAS – Committee of the World Underwater Federation
* Scientific diver training – Training divers who will be doing scientific work underwater
* Scientific diving – Use of diving techniques in the pursuit of scientific knowledge
* SCMBA – British military rebreather
* Scorpio ROV – Work class remotely operated underwater vehicle
* Scottish Sub Aqua Club (ScotSAC)
* Scour, also known as hydrodynamic scour – Removal of sediment near an obstruction by swiftly moving water
* Screw gate carabiner – Carabiner snap hook with screw lock gate
* Scrubber breakthrough – Failure mode in rebreathers when the carbon dioxide scrubber is exhausted
* Scrubber canister – Container for chemicals used to remove carbon dioxide from breathing gas
* Scrubber endurance – The duration that a rebreather scrubber can adequately remove carbon dioxide
* Scuba configuration – The arrangement of self contained breathing apparatus carried by a diver
* Scuba contents gauge – Submersible pressure gauge for scuba cylinders
* Scuba cylinder valve – Valve controlling flow of breathing gas into and out of a scuba cylinder
* Scuba diving – Swimming underwater, breathing gas carried by the diver
* Scuba diving equipment – Equipment needed for scuba diving
* Scuba diving fatalities – Deaths occurring while scuba diving or as a consequence of scuba diving
* Scuba diving in the Cayman Islands – Recreational diving tourism destination
* Scuba Diving International (SDI) – Recreational diver training and certification agency
* Scuba diving quarry – Disused and flooded quarry repurposed for underwater diving
* Scuba diving regulator – Device to supply breathing gas on demand to a scuba diver
* Scuba diving skills – The skills required to dive safely using self-contained underwater breathing apparatus
* Scuba diving therapy – Treatment using scuba diving activities
* Scuba diving tourism – Industry based on recreational diver travel
* Scuba Educators International (SEI) – Recreational diver training and certification agency
* Scuba emergency procedures, also known as scuba emergency skills – Standard procedures for use in common scuba diving emergencies
* Scuba endurance – How long a diver can breathe from a given scuba set, taking dive profile and activity into account
* Scuba equipment – Equipment needed for scuba diving
* Scuba fatalities – Deaths occurring while scuba diving or as a consequence of scuba diving
* Scuba finswimming – Underwater sport discipline
* Scuba gas blender – Person competent to blend breathing gases for scuba diving
* Scuba gas consumption – Breathing gas used while scuba diving
* Scuba gas management – Logistical aspects of scuba breathing gas
* Scuba gas monitoring – Keeping track of available breathing gas quantities
* Scuba gas planning – Estimation of breathing gas mixtures and quantities required for a planned dive profile
* Scuba gas reserve – Breathing gas reserved for contingencies
* Scuba gear – The equipment used by a scuba diver for diving
* Scuba harness – Equipment for supporting a scuba set on a diver
* Scuba isolation manifold – Component used to functionally connect and disconnect scuba cylinders
* Scuba manifold – Scuba component used to functionally connect diving cylinders
* Scuba mouthpiece – Bite grip breathing interface on demand valve
* Scuba orienteering – Underwater compass navigation and speed competition on scuba.
* Scuba procedures – Standardised methods for scuba diving activities
* Scuba refresher course – Coaching to restore skills and knowledge
* Scuba regulator – Mechanism that controls the pressure of a breathing gas supply for scuba diving
* Scuba regulator hose swivel – Connector between hose and first or second stage regulator allowing additional rotation
* Scuba replacement – Surface-supplied diving mode using only gas supplied from high pressure cylinders
* Scuba reserve valve – Scuba gas supply valve which is opened to release the gas held in reserve
* Scuba Schools International (SSI) – Recreational scuba and freediving training and certification agency
* Scuba set – Self-contained underwater breathing apparatus
* Scuba skills – The skills required to dive safely using a self-contained underwater breathing apparatus.
* Scubapro – Brand of scuba diving equipment
* SDBA – Special duty oxygen breathing apparatus, a military rebreather.
* SDI Computer Diver – Course for divers trained only on dive tables
* SDI Solo Diver – Original recreational certification specifically for solo diving

### Se

Section contents: Top of section, Sa–Sb, Sc–Sd, Se, Sh, Si–Sj, Sk, Sl, Sm, Sn, So, Sp–Sr, St, Su, Sw, Sy
* Seabed mining – Mineral recovery from the bottom of the sea
* Seabed tractor – Special purpose class of remotely operated underwater vehicle
* Sea Dragon-class ROV – Chinese deep diving work class remotely operated underwater vehicle
* Seafox drone – Remotely operated anti-mine marine drone
* Seaglider – Deep diving autonomous underwater vehicle for long term missions
* SeaKeys – Collaborative marine biodiversity project in South Africa
* SEALAB – Experimental underwater habitats developed by the United States Navy
* SEAL Delivery Vehicle – Manned wet submersible for deploying naval special forces
* Sea level atmospheric pressure – Static pressure exerted by the weight of the atmosphere at sea level
* SeaPerch – Remotely operated underwater vehicle educational program
* Sea Pole-class bathyscaphe – Chinese bathyscaphe class
* Sea Research Society – American nonprofit for marine research
* SEAL Delivery Vehicle (SDV) – Manned wet submersible for deploying naval special forces
* Search and recovery diver – Diver certified as trained in underwater search and recovery
* Willard Franklyn Searle – US Navy ocean engineer and developer of diving and salvage equipment and systems
* Seasickness, also known as motion sickness – Motion sickness occurring at sea
* Secondary regulator second stage – Second demand valve on a scuba regulator first stage
* Self-propelled hyperbaric lifeboat (SPHL) – Powered hyperbaric evacuation unit
* Self-reliant diver – Recreational diving certification
* Self-reliant diving – Philosophy and practice of diving that does not rely on assistance
* Self-rescue diver – Recreational diving certification
* Self-sufficient diver – Recreational diving certification
* Self-sufficient diving – Scuba diving with skill and equipment to manage most contingencies without assistance
* Semi-submersible platform – Marine vessel used in offshore roles with good stability and seakeeping
* Sentry (AUV) – Autonomous underwater vehicle
* Sewer diving – Diving for maintenance work in sewers

### Sh

Section contents: Top of section, Sa–Sb, Sc–Sd, Se, Sh, Si–Sj, Sk, Sl, Sm, Sn, So, Sp–Sr, St, Su, Sw, Sy
* Shadow Divers – Book by Robert Kurson recounting the discovery of a World War II German U-boat wreck
* Shallow-water blackout, also known as shallow water blackout – Loss of consciousness at a shallow depth during a dive
* Shallow Water Combat Submersible – Manned submersible and a type of swimmer delivery vehicle
* Shallow-water diving helmet, also known as shallow water helmet – Open-bottom diving helmet held on by weight
* Shark baiting – Attracting sharks by chumming the water
* Shark cage diving – Diving inside a protective cage to observe sharks in the wild
* Shark-proof cage – A metal structure to protect divers and snorkellers from potentially dangerous sharks
* Shark River Reef – Artificial reef off New Jersey
* Shark tourism – Tourism industry based on viewing wild sharks
* Shayetet 13 – Special operations unit of the Israeli Navy
* Shearwater Research – Canadian manufacturer of dive computers and rebreather electronics.
* Shilling, Charles Wesley – U.S. Navy physician, researcher, and educator
* Ships husbandry – Maintenance and upkeep of ships
* Ships husbandry diving – Diving related to the maintenance and upkeep of ships
* Shot-line, also known as shot line or shotline – Substantial weighted near-vertical line with buoy

### Si–Sj

Section contents: Top of section, Sa–Sb, Sc–Sd, Se, Sh, Si–Sj, Sk, Sl, Sm, Sn, So, Sp–Sr, St, Su, Sw, Sy
* Sidemount – Diving equipment configuration where scuba sets are clipped to the diver's sides
* Sidemount diver – Scuba certification for using scuba sets clipped to the sides of the harness
* Sidemount diving – Diving using equipment configuration where scuba sets are clipped to the diver's sides
* Sidemount harness – System connecting the sidemount scuba sets to the diver
* Sidemount rebreather – Diving rebreather designed to be mounted at the side of the diver
* Side-mount scuba – Scuba sets carried clipped to the sides of the diver's harness
* Side-slung bailout set – Bailout cylinder clipped to the side of the diver's back-mount cylinder harness
* Siebe, Augustus – British engineer mostly known for his contributions to diving equipment
* Siebe Gorman – British manufacturer of diving equipment and salvage contractor
* Siebe Gorman CDBA – Type of diving rebreather used by the Royal Navy
* Siebe Gorman Salvus – Industrial rescue and shallow water oxygen rebreather
* Signal tube – Inflatable buoy used by a diver at the surface to indicate position to the dive boat
* List of signs and symptoms of diving disorders – Evidence of physiological disorders resulting from underwater diving
* Silent bubbles – Asymptomatic decompression bubbles
* 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
* Silt out, also known as siltout, or silt-out – Reduction of underwater visibility by disturbing silt deposits
* Silt screw – A peg for insertion into soft sediment to locate a distance line
* Single atmosphere diving suit – Articulated pressure resistant anthropomorphic housing for an underwater diver
* Single-hose diving regulator, also known as single hose – Regulator with two stages connected by a low-ressure hose
* Single point of failure – A part whose failure will disrupt the entire system
* The Silent World: A Story of Undersea Discovery and Adventure – Book by Jacques-Yves Cousteau and Frédéric Dumas
* Siluro San Bartolomeo – Italian manned torpedo design of late WWII
* Single point of failure – A part whose failure will disrupt the entire system
* Sinking of MV Conception – 2019 maritime disaster
* Sinking of the Rainbow Warrior – 1985 covert attack by French foreign intelligence service on a Greenpeace ship
* Sinking ships for wreck diving sites – Scuttling old ships to produce artificial reefs
* Sinus squeeze – Barotrauma of the sinuses
* Sistema Huautla – Cave system in Oaxaca, Mexico
* Sistema Nohoch Nah Chich – Flooded cave system in Mexico
* Sistema Ox Bel Ha – Flooded cave system in Quintana Roo, Mexico
* Situation awareness – Adequate perception of environmental elements and external events
* Siva (rebreather) – Range of military rebreathers
* SJT-class ROUV – Series of Chinese remotely operated underwater vehicles

### Sk

Section contents: Top of section, Sa–Sb, Sc–Sd, Se, Sh, Si–Sj, Sk, Sl, Sm, Sn, So, Sp–Sr, St, Su, Sw, Sy
* Skandalopetra diving – Freediving using a stone weight at the end of a rope to the surface
* Skin bend – Decompression symptoms in superficial tissues
* Skindiving (disambiguation)

### Sl

Section contents: Top of section, Sa–Sb, Sc–Sd, Se, Sh, Si–Sj, Sk, Sl, Sm, Sn, So, Sp–Sr, St, Su, Sw, Sy
* Sladen Suit – Early British military drysuit
* Sling (rigging) – Rope, webbing, wire or chain used to support a load for lifting
* Sling cylinder – An independent scuba set carried clipped to the side of a scuba diver's harness
* Slingshot valve – Dual outlet scuba cylinder valve with Y-shape body

### Sm

* Smith, Gordon – Inventor of KISS diving rebreather, born 1950

### Sn

Section contents: Top of section, Sa–Sb, Sc–Sd, Se, Sh, Si–Sj, Sk, Sl, Sm, Sn, So, Sp–Sr, St, Su, Sw, Sy
* Snag-line search – Use of a taut line towed across the search area to catch on the target
* Snell's law, also known as law of refraction – Formula for refraction angles
* Snoopy loop, also known as ranger band – Rubber band made from inner tube
* Snorkel – Tube for breathing face down at the surface of the water
* Snorkel mask – Breathing apparatus for surface swimming
* Snorkeling – Swimming while inhaling through a snorkel
* Snorkeling vest, also known as snorkelling vest – Personal buoyancy aid for use while snorkeling
* Snuba – Limited depth airline breathing apparatus towed by the diver

### So

Section contents: Top of section, Sa–Sb, Sc–Sd, Se, Sh, Si–Sj, Sk, Sl, Sm, Sn, So, Sp–Sr, St, Su, Sw, Sy
* Società Anonima Lavorazioni Vari Appararecchi di Salvataggio (SALVAS) – Italian manufacturer of salvage and diving equipment
* Society for Underwater Historical Research – Amateur maritime archaeology organisation in South Australia
* Solo diver – Recreational diver diving without a dive buddy
* Solo Diver – SDI recreational diver self-sufficiency certification
* Solo diver certification – Original solo scuba diving certification
* Solo diving – Recreational diving without a dive buddy
* Solo diving skills – Additional scuba skills of self-reliance
* Solubility – Capacity of a substance to dissolve in a homogeneous way
* Solution – Homogeneous mixture of a solute and a solvent
* Sonar – Acoustic sensing method
* Sonar imaging – Constructing digital images from sonar data
* Sonic orifice – Orifice undergoing choked flow of a compressible medium
* South African Association for Marine Biological Research (SAAMBR) – Non profit conservation research organisation based in Durban, SA
* South African Department of Employment and Labour – Department of the South African government responsible for matters related to employment
* South African Environmental Observation Network (SAEON) – A network to perform long-term ecological research in South Africa and surrounding waters
* South African Underwater Sports Federation (SAUSF) – Official World Underwater Federation representative body in the Republic of South Africa
* South Pacific Underwater Medicine Society (SPUMS) – Publisher for diving and hyperbaric medicine and physiology
* South Pacific Underwater Medical Society Journal – Journal covering underwater and hyperbaric medicine and physiology
* Southern African Underwater and Hyperbaric Medical Association (SAUHMA) – Special interest group of the Council of the South African Medical Association

### Sp–Sr

Section contents: Top of section, Sa–Sb, Sc–Sd, Se, Sh, Si–Sj, Sk, Sl, Sm, Sn, So, Sp–Sr, St, Su, Sw, Sy
* SP-350 Denise – French two-person submarine
* Spearfisherman (company) – American diving equipment manufacturer
* Spearfishing – Hunting for fish using a spear
* Speargun – Underwater fishing implement
* Special Actions Detachment – Special operations maritime unit of the Portuguese Navy
* Special Air Service – Special forces of the British Army
* Special Air Service Regiment – Special forces unit of the Australian Army
* Special Boat Service – Special forces unit of the Royal Navy
* Special Duties Unit – Hong Kong Police tactical unit
* Special Forces Command (Turkey) – Turkish special forces group
* Special Forces Group (Belgium) – Special forces unit in the Belgian Armed Forces
* Special Operations Battalion (Croatia) – Special forces military unit
* Special Service Group (Navy) – Special operations force of the Pakistan Navy
* Special Warfare Diving and Salvage – Bangladesh Navy special operations force
* Speleonaut – Diver propulsion vehicle designed for cave exploration by a disabled diver
* Spindle (vehicle) – Ice penetrating two-stage autonomous underwater vehicle
* Spiral box search – Search pattern expanding stepwise outward from datum
* Spitcock – Valve on diving helmet to provide water for the diver to spit on inside of viewport
* Sponge diving – Diving to gather natural sponges
* Sport (shipwreck) – Tugboat wrecked in Lake Huron
* Sport diving (sport) – Underwater sport using recreational open circuit scuba equipment in a swimming pool
* SPP-1 underwater pistol – Soviet four-barreled underwater dart pistol
* SPUMS – Publisher for diving and hyperbaric medicine and physiology
* SPURV – Self propelled underwater research vehicle built in 1957 for the US Navy
* SPURV II – Special purpose underwater research vessel built to srudy submarine wakes
* Squeeze (diving) – Barotrauma of descent
* SRV-300 – Deep-submergence rescue vehicle

### St

Section contents: Top of section, Sa–Sb, Sc–Sd, Se, Sh, Si–Sj, Sk, Sl, Sm, Sn, So, Sp–Sr, St, Su, Sw, Sy
* Stabilizer jacket – Configuration of diving buoyancy compensator
* Stage cylinder – Diving cylinder intended to be collected for use on the return part of a scuba dive
* Staged deccompression, also known as stage decompression – Decompression with stops at specific depths
* Stage drop, also known as stage-drop – Placing a scuba cylinder at the distance line for planned later use.
* Stage rigging (scuba) – Clips, cords and straps on a scuba cylinder to attach it to a diver
* Stage set (scuba) – Scuba set to be used during a stage of a dive
* Standard diving dress – Copper helmet with rubberised canvas diving suit and weighted boots
* Standard diving equipment – Copper helmet with rubberised canvas diving suit and weighted boots
* Standard diving helmet – Copper free-flow helmet system used with Standard Diving Dress
* Standard helmet – Helmet of standard diving dress
* Standard operating procedure – Set of detailed instructions to assist in workplace safety
* Standard procedure – A recommend way to do something that is known to be effective and safe
* Standby diver, also known as stand-by diver – Diver who is ready to go to the assistance of the working diver
* Standby diving – Diving as a safety attendant to the working diver
* Standard diving dress – Copper helmet with rubberised canvas diving suit and weighted boots
* Standard operating procedure – Set of detailed instructions to assist in workplace safety
* Star Canopus diving accident – Fatal offshore diving bell accident in 1978
* Static apnea – Stationary diving discipline of holding breath underwater
* Stena Seaspread diving accident – Saturation diving bell incident with successful rescue in the North Sea in 1981
* Stratification – Layering of a body of water due to density variations
* Stress exposure training – Training in a deliberately distracting environment
* Striver (bathyscaphe), also known as Struggler (bathyscaphe) – Chinese deep submergence vehicle

### Su

Section contents: Top of section, Sa–Sb, Sc–Sd, Se, Sh, Si–Sj, Sk, Sl, Sm, Sn, So, Sp–Sr, St, Su, Sw, Sy
* Sub-Aqua Association (SAA) – British recreational diver training and certification organisation
* Submarine emergency gas supply – Breathing gas system installed in submarine for emergency use
* Submarine Escape Immersion Equipment – Whole-body exposure suit that allows submariners to escape from a sunken submarine
* Submarine escape set – Self contained breathing apparatus providing gas to escape from a submerged submarine
* Submarine escape training facility – Facility used for training submariners in methods of escape from a sunken submarine
* Submarine Escape Training Facility (Australia) – Shore facility of the Royal Australian Navy
* Sub Marine Explorer – Early submarine craft
* Submarine pipeline – Pipeline that is laid on the seabed or below it inside a trench
* Submarine Products – Former British diving equipment manufacturer and distributor.
* Submarine rescue – Rescue of personnel from a disabled submarine
* Submarine rescue chamber – Diving chamber for rescue of personnel of sunk submarines
* Submarine Rescue Diving Recompression System – Remotely operated vehicle for rescue of personnel from sunken submarines
* Submarine rescue ship – Support ship for submarine rescue and deep-sea salvage operations
* Submersible pressure gauge – Pressure measuring instrument for underwater service
* Subskimmer – Submersible diver propulsion vehicle with inflatable buoyancy for surface use
* Subsurface (software) – Open source software for logging and planning scuba dives
* Suit squeeze – Barotrauma caused by the folds of a diving suit piching the skin
* Superoxide scrubber – Breathing gas scrubber that adds oxygen and removes carbon dioxide
* Supersaturation – State of a solution that contains more solute than can be dissolved at equilibrium
* Supervised diver – Minimum requirements for a recreational diver to dive in open water under direct supervision
* Supply lock – Small airlock to transfer supplies between areas of different pressure
* Support diver – Recreational diving equivalent of a stand-by diver
* Surface blackout – Loss of consciuosness immediately following surfacing of a freediver
* Surface decompression – Decompression in a diving chamber out of the water
* Surface decompression on oxygen – Staged decompression obligation done in a decompression chamber
* Surface interval – The time spent out of the water between dives
* Surface marker buoy – Buoy towed by a scuba diver to indicate position
* Surface oriented diving – Underwater diving in which the diver starts and finishes at surface pressure
* Surface stand-by diver procedures – Functions of member of a professional diving team
* Surface-supplied air diver – Person competent to dive with surface-supplied breathing apparatus
* Surface-supplied breathing apparatus – Equipment to supply a diver with breathing gas at ambient pressure from the surface
* Surface-supplied diver, also known as surface supplied diver – Underwater diver breathing gas supplied from the surface
* Surface-supplied diving – Underwater-diving breathing gas supplied from the surface
* Surface-supplied diving emergency procedure, also known as surface-supplied diving emergency skill – Standard procedures for use in common surface-supplied diving emergencies
* Surface-supplied diving equipment – Equipment used specifically for surface supplied diving
* Surface-supplied diving procedures – Procedures used in the safe operation and use of surface-supplied diving equipment
* Surface-supplied diving skills, also known as surface supplied diving skills – Skills and procedures required for the safe operation and use of surface-supplied diving equipment
* Surface-supplied gas management – Provision of breathing gas to surface-supplied divers
* Surface-supplied mixed gas diver – Person competent to dive with mixed gas from a closed bell
* Surface tension – Tendency of a liquid surface to shrink to reduce surface area
* Surface water searches – Procedures to find objects or persons lost at the surface of a body of water
* Surface tension – Tendency of a liquid surface to shrink to reduce surface area
* Surfactant – Substance that lowers the surface tension between a liquid and another material
* Surfer's ear – Common name for an abnormal bone growth within the external ear canal
* Surge (wave action) – The component of wave motion close to and parallel with the bottom
* Sustained load cracking – Metallurgical failure mode of cracking under a prolonged static load
* Suunto – Finnish manufacturer of compasses, dive computers and sports watches

### Sw

Section contents: Top of section, Sa–Sb, Sc–Sd, Se, Sh, Si–Sj, Sk, Sl, Sm, Sn, So, Sp–Sr, St, Su, Sw, Sy
* Swedish Armed Forces Diving and Naval Medicine Centre – Diver education and training; diving medicine research and development
* Swimfin – Footwear used for personal propulsion through water
* Swimming – Self-propulsion through water
* Swimming-induced pulmonary edema – Body fluid in the lungs while swimming.
* Swim-through – Short underwater tunnel with adequate clearance and obvious exit

### Sy

Section contents: Top of section, Sa–Sb, Sc–Sd, Se, Sh, Si–Sj, Sk, Sl, Sm, Sn, So, Sp–Sr, St, Su, Sw, Sy
* Systemic circulation – Portion of the cardiovascular system which transports oxygenated blood away from the heart
* Systems technician – Person competent to maintain diving systems
| 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 |