使用者討論:Farm/TMP

Signal flag A(Alpha) - "I have a diver down - Keep clear"

Informal Recreational diving flag

潛水是一項水下活動，有的需要呼吸裝備（水肺潛水和送氣式潛水），有的則依靠屏氣（自由潛水）。

休閒潛水是一種流行的活動，也被稱為運動潛水；而專業潛水（商業潛水，出於科學研究或經濟目的）則在水下潛點實施作業。

潛水類型決定了不同的訓練、裝備類型以及呼吸氣體。

潛水包括自由潛水、水肺潛水、送氣式潛水、飽和潛水以及深海潛水。

• 
  用monofin自由潛水，上升中
• 
  休閒的水肺潛水員
• 
  送氣式潛水員駕馭平台抵達水下工作站
• 
  封閉倉將飽和潛水員從工作檯運至高壓生命倉
• 
  美國海軍大氣潛水系統 (ADS)

歷史

早在古希臘，商業而不是休閒目的的潛水就已開始，當時柏拉圖和荷馬有提及將海綿動物門用作洗澡。卡林諾斯島是潛水捕獲海綿動物門的主要地點。通過使用多達15公斤（33英磅）的配重（skandalopetra）來加速下潛，屏氣潛水員在5 分鐘內可下潛至30公尺（98英尺）以收集海綿動物門。

潛水的方式

不帶呼吸器的潛水

自由潛水

主條目：自由潛水

自由潛水不用任何呼吸設備，僅依靠潛水員的屏氣能力，包括簡單的屏氣潛水以及競爭的極限下潛。

游泳

主條目：游泳

在水裡游泳或下潛可以是一項實用的緊急技能，在水上運動和海軍安全訓練中是重要組成部分。通常而言，從高處跳水也是一項有趣的休閒活動，無論是否帶有呼吸器。

浮潛

主條目：浮潛

增加了一根呼吸管，這樣可以把臉朝向水底，身體浮在水面。

水肺潛水

主條目：水肺潛水

水肺潛水通過自給式潛水呼吸器，而無需水面送氣，這樣潛水員在水下就可以靈活移動。

一些水肺潛水員還被稱為蛙人，尤其是部隊裡從事秘密行動的潛水員。

開環

主條目：Scuba set

開環水肺系統將呼出的氣體直接排到周圍環境，裝置包括一個或多個高壓潛水空氣瓶，空氣瓶又和[[潛水呼吸調節器]相連，同時也可能包括另外的應急空氣瓶。

再呼吸

主條目：Rebreather

閉環或半閉環呼吸系統重複利用呼出的氣體，這樣就可以減少用氣量。和開環潛水相比，相同的潛水過程，潛水員可以背更小的空氣瓶；而對於同樣的空氣消耗，潛水員可以在水下待更長的時間。再呼吸潛水產生的氣泡和噪音也更少，所以在軍事、科研和媒體領域，更受歡迎。

送氣式潛水

展銷會上展示的送氣式商業潛水裝備

主條目：surface supplied diving

與自帶呼吸系統相對的是水面送氣，水面通過臍帶纜或航空軟管提供空氣、通訊以及安全線，甚至還可以提供加熱的熱水軟管、視頻纜線和空氣回收纜線。

Surface oriented diving

Surface oriented, or bounce diving, is how commercial divers refer to diving operations where the diver starts and finishes the diving operation at atmospheric pressure. The alternative is saturation diving.

The diver may be deployed directly, often from a diving support vessel or indirectly via a diving bell. Surface-supplied divers almost always wear diving helmets or full face diving masks. The bottom mix can be air or mixed gas, the decompression mix nitrox or pure oxygen. Decompression procedures include in-water decompression or surface decompression in a deck chamber.

A wet bell with a gas filled dome provides more comfort and control than a stage and allows for longer time in water. Wet bells are used for air and mixed gas, and divers can decompress on oxygen at 12 m.

Small closed bell systems have been designed that can be easily mobilized, and include a two-man bell, a handling frame and a chamber for decompression after transfer under pressure (TUP). Divers can breathe air or mixed gas at the bottom but are usually recovered in the chamber filled with air. They decompress on oxygen supplied through built in breathing systems (BIBS) towards the end of the decompression. Small bell systems support bounce diving down to 120 m and for bottom times up to 2 hours.

An alternative to scuba diving, called "SNUBA" or "hooka" diving, has the diver supplied via an airline from a small cylinder or compressor at the surface. It is used for light work such as hull cleaning and archaeological surveys, for shellfish harvesting, and as a shallow water tourist activity for those who are not scuba-certified.

Saturation diving

主條目：Saturation diving

Saturation diving lets professional divers live and work at depth for days or weeks at a time. This type of diving allows greater economy of work and enhanced safety. After working in the water, divers rest and live in a dry pressurized underwater habitat on the bottom or a saturation life support system of pressure chambers on the deck of a diving support vessel, oil platform or other floating work station. In either case, they stay at a similar pressure to the work depth. They may be transferred in a closed diving bell, also known as a personnel transfer capsule. Decompression at the end of the dive may take many days, but since it is done only once for a long period of exposure, rather than after each of many shorter exposures, the overall risk of decompression injury to the diver and the total time spent decompressing are reduced.

潛水的動機

Professional diver using surface supplied diving equipment performing underwater welding

參見：Recreational diving和Professional diving

Diving may be done for a number of reasons, both personal and professional.

Recreational diving, is purely for enjoyment and has a number of distinct technical disciplines to increase interest underwater, such as cave diving, wreck diving, ice diving and deep diving.

Divers may be employed professionally to perform tasks underwater.

Commercial divers are employed to perform tasks related to industries involving underwater work, including civil engineering tasks such as in oil exploration, offshore construction dam maintenance and harbour works. Commercial divers may also be employed to perform tasks specifically related to marine activities, such as naval diving, including the repair and inspection of boats and ships, salvage of wrecks or aquaculture.

There are a fair number of divers who work, full or part-time, in the recreational diving community as instructors, assistant instructors, divemasters and dive guides. In some jurisdictions the professional nature, with particular reference to responsibility for health and safety of the clients, of recreational diver instruction, dive leadership for reward and dive guiding is recognised by national legislation.

Other specialist areas of diving include military diving, with a long history of military frogmen in various roles. They can perform roles including direct combat, infiltration behind enemy lines, placing mines, bomb disposal or engineering operations.

In civilian operations, many police forces operate police diving teams to perform search and recovery or search and rescue operations and to assist with the detection of crime which may involve bodies of water. In some cases diver rescue teams may also be part of a fire department, paramedical service or lifeguard unit, and may be classed as public safety diving.

Lastly, there are professional divers involved with the water itself, such as underwater photography or underwater film makers, who set out to document the underwater world, or scientific diving, including marine biology, geology, hydrology, oceanography and underwater archaeology.

The choice between scuba and surface supplied diving equipment is based on both legal and logistical constraints. Where the diver requires mobility and a large range of movement, scuba is usually the choice if safety and legal constraints allow. Higher risk work, particularly commercial diving, may be restricted to surface supplied equipment by legislation and codes of practice.

Reasons for diving may include:

Diving activities	Classification	Scuba or Surface Supplied Diving Equipment
aquarium maintenance in large public aquariums	commercial, scientific	Scuba, SSDE
boat and ship inspection, cleaning and maintenance	commercial, naval	SSDE, occasionally scuba
cave diving	technical, recreational, scientific	Scuba, occasionally SSDE
civil engineering in harbors, water supply, and drainage systems	commercial	Almost exclusively SSDE
crude oil industry and other offshore construction and maintenance	commercial	Almost exclusively SSDE
demolition and salvage of ship wrecks	commercial, naval	SSDE, sometimes scuba
professional diver training	professional	SSDE or scuba as appropriate
recreational diver training	professional, recreational	Scuba
fish farm maintenance	commercial	Scuba, SSDE
fishing, e.g. for abalones, crabs, lobsters, pearls, scallops, sea crayfish, sponges	commercial	Scuba, SSDE
frogman, manned torpedo	military	Scuba
harbor clearance and maintenance	commercial, military	Almost exclusively SSDE
media diving: making television programs, etc.	professional	Scuba, occasionally SSDE
mine clearance and bomb disposal, disposing of unexploded ordnance	military, naval	Scuba, occasionally SSDE
pleasure, leisure, sport	recreational	Almost exclusively scuba
policing/security: diving to investigate or arrest unauthorized divers	police diving, military, naval	Scuba
search and recovery diving	commercial, public safety, police diving	Scuba, SSDE
search and rescue diving	police, naval, public service	Scuba, occasionally SSDE
spear fishing	professional (occasionally), recreational	Scuba
stealthy infiltration	military	Scuba
surveys and mapping	scientific, recreational	Scuba, SSDE
scientific diving (marine biology, oceanography, hydrology, geology, palaeontology, diving physiology and medicine)	scientific	Scuba, occasionally SSDE
underwater archaeology (shipwrecks; harbors, and buildings)	scientific, recreational	Scuba, SSDE
underwater inspections and surveys	commercial, military	SSDE, sometimes scuba
underwater photography	professional, recreational	Scuba, SSDE
underwater sport	recreational	Snorkel, breathhold and Scuba
underwater tour guiding	professional, recreational	Scuba
underwater tourism	recreational	Scuba, occasionally Snuba
underwater welding	commercial	Almost exclusively SSDE

• 
  Early underwater photographer (1960's)

潛水的訓練

主條目：Diver training

Underwater diver training is normally given by a qualified instructor who is a member of one of many diving training agencies or is registered with a government agency.

Basic diver training entails the learning of skills required for the safe conduct of activities in an underwater environment, and includes procedures and skills for the use of diving equipment, safety, emergency self-help and rescue procedures, dive planning, and use of dive tables.

Some of the skills which an entry level diver will normally learn include:

• Ear equalization and equalisation of other air spaces.
• Underwater breathing – the skill of breathing through the apparatus.
• Mask clearing – the skill of clearing water from the mask.
• Air sharing – assisting another diver by providing air from one's own supply, or receiving air supplied by another diver.
• Emergency ascents - how to return to the surface without injury in the event of a breathing supply interruption.
• Use of bailout systems (professional divers)
• Buoyancy control – neutral buoyancy allows the diver to move about underwater comfortably.
• Diving signals – used to communicate underwater. Professional divers will also learn other methods of communication.

潛水的危害

主條目：Diving hazards and precautions

Divers face specific physical and health risks when they go underwater with scuba or other diving equipment, or use high pressure breathing gas. The hazards can be listed under several categories:

• The aquatic environment
• Use of breathing equipment in an underwater environment
• Exposure to a pressurised environment and pressure changes, which includes:

• Pressure changes during descent
• Pressure changes during ascent
• Breathing gases at high ambient pressure

• The specific diving environment
• Pre-existing physiological and psychological conditions in the diver
• Diver behaviour and competence
• Failure of diving equipment other than breathing apparatus
• Hazards of the dive task and special equipment
• Hazards related to access to and egress from the water.

The presence of a combination of several hazards simultaneously is common in diving, and the effect is generally increased risk to the diver, particularly where the occurrence of an incident due to one hazard triggers other hazards with a resulting cascade of incidents. Many diving fatalities are the result of a cascade of incidents overwhelming the diver, who should be able to manage any single reasonably foreseeable incident.

The assessed risk of a dive would generally be considered unacceptable if the diver is not expected to cope with any single reasonably foreseeable incident with a significant probability of occurrence during that dive. Precisely where the line is drawn depends on circumstances. Commercial diving operations tend to be less tolerant of risk than recreational, particularly technical divers, who are less constrained by occupational health and safety legislation.

According to a North American 1972 analysis of calendar year 1970 data, diving was, based on man hours, 96 times more dangerous than driving an automobile. According to a 2000 Japanese study, every hour of recreational diving is 36 to 62 times riskier than automobile driving.

Consequences of diving hazards range from merely annoying through to rapidly fatal, and are listed in the article on Diving hazards and precautions and discussed in detail in other articles linked from that article.

潛水的其他形式

Diving in submersibles

Submarines, submersibles and 'hard' diving suits enable undersea diving to be carried out within a dry environment at normal atmospheric pressure, albeit more remotely. Underwater robots and remotely operated vehicles and also carry out some functions of divers at greater depths and in more dangerous environments.

Diving by other animals

Humans are not the only air-breathing creatures to dive. Marine mammals such as seals, dolphins and whales, dive to feed and catch prey under the sea as do penguins and many seabirds, as well as various reptiles: turtles, saltwater crocodiles, seasnakes and Marine Iguanas. Many mammals, birds and reptiles also dive in freshwater rivers and lakes.

延伸閱讀

• Cousteau J.Y. (1953) Le Monde du Silence, translated as The Silent World, Hamish Hamilton Ltd., London; ASIN B000QRK890
• Lang M.A. & Brubakk A.O. (eds., 2009) The Future of Diving: 100 Years of Haldane and Beyond, Smithsonian Institution Scholarly Press, Washington DC