Diving activities are the things people do whilediving underwater. People may dive for various reasons, both personal and professional. While a newly qualified recreational diver may dive purely for the experience of diving, most divers have some additional reason for being underwater.Recreational diving is purely for enjoyment and has several specialisations andtechnical disciplines to provide more scope for varied activities for which specialist training can be offered, such ascave diving,wreck diving,ice diving anddeep diving.[1][2] Severalunderwater sports are available for exercise and competition.[3]
There are various aspects ofprofessional diving that range from part-time work to lifelong careers. Professionals in the recreational diving industry include instructor trainers, diving instructors, assistant instructors,divemasters, dive guides, and scuba technicians. Ascuba diving tourism industry has developed to service recreational diving in regions with popular dive sites. Commercial diving is industry related and includescivil engineering tasks such as inoil exploration,offshore construction, dam maintenance and harbour works. Commercial divers may also be employed to perform tasks related to marine activities, such asnaval diving,ships husbandry,marine salvage oraquaculture.[4][5][6] Other specialist areas of diving includemilitary diving, with a long history of militaryfrogmen in various roles. They can perform roles including direct combat, reconnaissance, infiltration behind enemy lines, placing mines,bomb disposal or engineering operations.[7]
In civilian operations,police diving units perform search and rescue operations, and recover evidence. In some casesdiver rescue teams may also be part of afire department,paramedical service,sea rescue orlifeguard unit, and this may be classed aspublic safety diving.[8][9] There are also professionalmedia divers such asunderwater photographers andvideographers, who record the underwater world, andscientific divers in fields of study which involve the underwater environment, includingmarine biologists,geologists,hydrologists,oceanographers andunderwater archaeologists.[10][6][11]
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.[12][11][13]
The standard procedures and activities essential to safe diving in the chosendiving mode, using the chosendiving equipment, and in the chosendiving environment are inherently part of the activities of a dive. Monitoring the dive profile, gas supplies, decompression status, relative positions of the divers and communication associated with these are all standard operating procedures. Contingency procedures associated with the diving mode, equipment and foreseeable diversions from the dive plan may also be necessary. These activities may be considered as occurring in the background, as in most cases they are not the reason for the dive.[14][15]
Navigation is a common activity during dives. Diver navigation, termed "underwater navigation" by scuba divers,[16] is a set of techniques—including observing natural features, the use of a compass, and surface observations—that divers use tonavigateunderwater.Free-divers do not spend enough time underwater for navigation to be important, andsurface supplied divers are limited in the distance they can travel by the length of theirumbilicals and are usually directed from the surface control point. On those occasions when they need to navigate they can use the same methods used by scuba divers. When it is critical for safety to return to a specific place, adistance line is generally used. This may be laid and left in place for other divers, or recovered on the return leg. Use of distance lines is standard inpenetration diving, where the divers cannot ascend directly to the surface at all times, and it is possible to lose track of the route out toopen water.[17][18][19]
Searches are a fairly common diving activity, and may be the primary purpose of the dive, part of a more complex activity plan, or incidental. Underwater searches are procedures to find a known or suspected target object or objects in a specified search area under water. A search method attempts to provide full coverage of the search area, by using a search pattern, which should completely cover the search area without excessive redundancy or missed areas.[20][21][22]
Adiver propulsion vehicle is a type of diving equipment sometimes used by scuba divers to increase range underwater. Range is restricted by the amount of breathing gas that can be carried, the rate at which that breathing gas is consumed, and the battery power of the DPV. Time limits imposed on the diver by decompression requirements may also limit safe range in practice. DPVs have recreational, scientific and military applications.[23][24][25]
There is often an element of exploration in diving activity, as it is common to dive in an unfamiliar place. This exploration may be casual or focused on gathering information which can be shared or recorded and published for use by others. A large part of the waters accessible to divers remains virtually unknown, and has not been surveyed or mapped in detail, and in many cases, has not yet been visited by divers. Exploration has been identified as one of the major motivations for recreational diving, but it is mostly casual and seldom results in recorded reports which can be of use to others.
Underwater work is usually done by professional divers who are paid for their work. Theprocedures are often regulated by legislation and codes of practice as it is an inherentlyhazardous occupation and the diver works as a member of ateam. Due to the dangerous nature of some professional diving operations, specialized equipment such as an on-sitehyperbaric chamber and diver-to-surface communication system is often required by law, and the mode of diving for some applications may be regulated.[13][26]
There are several branches of professional diving, the best known of which is probably commercial diving and its specialised applications. There are also applications inscientific research,marine archaeology,fishing andaquaculture,public service,law enforcement,military service,media work anddiver training. Specialist training may be required for some aspects of this work.
Commercial diving may be considered an application ofprofessional diving where the diver engages in underwater work for industrial, construction, engineering, maintenance or other commercial purposes which are similar to work done out of the water, and where the diving is usually secondary to the work.
Commercial offshore diving, sometimes shortened to just offshore diving, generally refers to the branch ofcommercial diving, with divers working in support of the exploration and production sector of theoil and gas industry. The work in this area of the industry includes maintenance ofoil platforms and the building of underwater structures. In this context "offshore" implies that the diving work is done outside ofnational boundaries. Technically it also refers to any diving done in the international offshore waters outside of the territorial waters of a state, where national legislation does not apply. Most commercial offshore diving is in theexclusive economic zone of a state, and much of it is outside the territorial waters. The type of work includes tasks such aswellhead completion,submarine pipeline monitoring and inspection, assembly of manifolds and work onmoorings, includingrigging,lifting, and assembly of components.[27]
Salvage diving is the diving work associated withmarine salvage, the recovery of all or part of ships, theircargoes, aircraft, and other vehicles andstructures which have sunk or fallen into water. In the case of ships it may also refer to repair work done to make anabandoned ordistressed but still floating vessel more suitable for towing or propulsion under its own power. Therecreational/technical activity known aswreck diving is generally not considered salvage work, though some recovery ofartifacts may be done by recreational divers.
Most salvage diving iscommercial ormilitary work, depending on the diving contractor and the purpose for the salvage operation, Similar underwater work may be done by divers as part offorensic investigations into accidents, in which case the procedures may be more closely allied withunderwater archaeology than the more basic procedures of advantageouscost/benefit expected in commercial and military operations.[28][29]
Hazmat diving generally refers to the presence ofhazardous materials in the diving environment, but some classes of underwater work are inherently in a hazardous materials environment, includingnuclear diving andsewer diving.[30]
Inspection of underwater structures, installations, and sites is a common professional diving activity, applicable to planning, installation, and maintenance phases, but the required skills are often specific to the application. Much use is made of video and still photographic evidence, and live video to allow direction of the inspection work by the supervisor and topside specialists. Inspections may also involve surface preparation, often by cleaning, and non-destructive testing.[31]
Potable water diving is diving inside atank that is used forpotable water. This is usually done for inspection and cleaning tasks. A person who is trained to do this work may be described as a potable water diver. The risks to the diver associated with potable water diving are related to the access, confined spaces and outlets for the water. The risk of contamination of the water is managed by isolating the diver in a clean dry-suit and helmet or full-face mask which are decontaminated before the dive.[30]
Ships husbandry is all aspects of maintenance, cleaning,[32] and general upkeep of thehull,rigging, and equipment of a ship. It may also be used to refer to aspects of maintenance which are not specifically covered by the technical departments.[33] The term is used in both naval and merchant shipping,[34] but 'naval vessel husbandry' may also be used for specific reference to naval vessels.[35] Underwater ships husbandry includes hull cleaning, inspection, and some kinds of repair work.[36]
Underwater construction isindustrial construction in anunderwater environment. There is often, but not necessarily, a significant component ofcommercial diving involved.[37][38] It is a part of themarine construction industry.[39]Concrete work is a common component of underwater construction, and may involve site clearing and preparation bysuction dredging,airlifting, high pressure and abrasivewaterjetting,in-water surface cleaning usingbrushcarts,shuttering and formwork, bagwork, and setup ofreinforcement. Underwater concrete placement may be bytremie,pumped concrete,skip placement, ortoggle bags.Concrete repair, and assembly of pre-cast components often involvesgrouting. Other work may include fitting fixing bolts by drilling andcore drilling, pipe installation (outfalls), pipeline support and protection, using mattresses for ballast and scour protection, andunderwater welding.
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Underwater divers may be employed in any branch of an armed force, including the navy, army, marines, air force and coast guard.Scope of operations includes:search and recovery,search and rescue,hydrographic survey,explosive ordnance disposal,demolition, underwater engineering,salvage,ships husbandry, reconnaissance, infiltration, sabotage, counterinfiltration,underwater combat andsecurity.[40]
Clearance diving, the removal of obstructions and hazards to navigation, is closely related to salvage diving, but has a different purpose, in that the objects to be removed are not intended to be recovered, just removed or reduced to a condition where they no longer constitute a hazard or obstruction. Many of the techniques and procedures used in clearance diving are also used in salvage work.
Submarine rescue is the process of locating a sunksubmarine with survivors on board, and bringing the survivors to safety.[41] This may be done by recovering the vessel to the surface first, or by transferring the trapped personnel to arescue bell ordeep-submergence rescue vehicle to bring them to the surface. Submarine rescue may be done at pressures between ambient at depth, and sea level atmospheric pressure, depending on the condition of the disabled vessel and the equipment used for the rescue.[41] Associated diving work may include preparing the submarine for access by a rescue bell or rescue submersible, if the depth allows human intervention. Recent developments tend to favour the use of remotely operated vehicles dedicated to this application.
Public safety diving is underwater diving conducted as part oflaw enforcement andsearch and rescue. Their work includes underwater rescue, underwater recovery and underwater investigation conducted by divers working for or under the authority of municipal, state or federal agencies. These divers are typically members of police departments, sheriff's offices, fire rescue agencies, search and rescue teams or providers of emergency medical services. Public safety divers differ from recreational, scientific and commercial divers who can generally plan the date, time, and location of a dive, and dive only if the conditions are conducive to the task. Public safety divers respond to emergencies 24 hours a day, 7 days a week, and may be required to dive in the middle of the night, during inclement weather, in zero visibility "black water," or in waters polluted by chemicals and biohazards. Much of their work involvesUnderwater searches.[8]
Police diving is a branch ofprofessional diving carried out bypolice services. Police divers are usually sworn police officers, and may either be employed full-time as divers or as generalwater police officers, or be volunteers who usually serve in other units but are called in if their diving services are required. The duties carried out by police divers includerescue diving for underwater casualties andsearch and recovery diving forevidence and bodies.[42]
Scientific diving is the use ofunderwater diving techniques by scientists to perform work underwater in the direct pursuit of scientific knowledge.[11] Scientific divers are normally qualified scientists first and divers second, who use diving equipment and techniques as their way to get to the location of their fieldwork. The direct observation and manipulation of marine habitats afforded to scuba-equipped scientists have transformed the marine sciences generally, andmarine biology andmarine chemistry in particular.[43]Underwater archeology andgeology are other examples of sciences pursued underwater. Some scientific diving is carried out by universities in support of undergraduate or postgraduate research programs, and government bodies such as theUnited States Environmental Protection Agency and the UKEnvironment Agency carry out scientific diving to recover samples of water, marine organisms and sea, lake orriverbed material to examine for signs of pollution.
Activities are widely varied and may include visual counts and measurements of organisms in situ, collection of samples,underwater surveys, photography, videography, video mosaicing, benthic coring, coral coring, and deployment, maintenance and retrieval ofscientific equipment.[44][45][46] Surveys include site surveys, geological surveys,baseline and monitoring ecological surveys, which may involve the use oftransect andquadrat methodology. A bibliographic analysis of papers published between 1995 and 2006 that have been supported by scientific diving shows that diving supports scientific research through efficient and targeted sampling. Activities include collection of specimen organisms and biological samples, observing and recording animal behaviour, quantitative surveys,in situ measurements, impact studies, ecological analyses, evaluation of techniques, mapping underwater areas, profiling geology, and deploying and retrieving underwater equipment.[47]
Media diving isunderwater diving in support of the media industries, including the practice ofunderwater photography and underwater cinematography andunderwater videography outside of normal recreational interests.[48] Media diving is often carried out in support of television documentaries featuring underwater photography or footage. Media divers are normally highly skilled camera operators who use diving as a method to reach their workplace, although some underwater photographers start as recreational divers and move on to make a living from their hobby. Equipment in this field is varied with scuba and surface supplied equipment used, depending on requirements, butrebreathers are often used for wildlife related work as they are normally quiet, release few or no bubbles and allow the diver a lengthy bottom time with a reduced risk of frightening off the subject.[49]
Scuba diving tourism is the industry based on servicing the requirements ofrecreational divers at destinations other than where they live. It includes aspects of training, equipment sales, rental and service, guided experiences andenvironmental tourism.[50][51] The diving activity most associated with work in the diving tourism industry is leading dives.Dive leader is the title of an internationally recognised recreational diving certification for the occupation of "dive guide", which is a specialist underwater application of "tour guide".[52][53] Several other titles are also used, including "Divemaster". This is a role that includes organising and leading recreational dives, particularly in a professional capacity,
Diver training is the set of processes through which a person learns the necessary and desirable skills tosafelydive underwater within the scope of thediver training standard relevant to the specific training programme. Most diver training follows procedures and schedules laid down in the associated training standard, in a formal training programme, and includes practical skills training in the safe use of the associatedequipment in the specified underwater environment, andassessment of the required skills and knowledge deemed necessary by thecertification agency to allow the newly certified diver to dive within the specified range of conditions at an acceptable level ofrisk. Practical training and assessment of skills largely occurs underwater, in the presence of adiving instructor, who is responsible for the safety of the trainee while under instruction or assessment.
Aquaculture is the controlled cultivation ("farming") ofaquatic organisms such asfish,crustaceans,mollusks,algae and other organisms of value such asaquatic plants (e.g.lotus).Aquaculture involves cultivatingfreshwater,brackish water andsaltwater populations under controlled or semi-natural conditions, and can be contrasted withcommercial fishing, which is the harvesting ofwild fish. There are many underwater activities associated with aquaculture which can be done by divers, including monitoring stock health and fish pen maintenance.[54]
Spearfishing is a method offishing that involves impaling the fish with a straight pointed object such as aspear,gig orharpoon. It has been deployed inartisanal fishing throughout the world for millennia. Modern spearfishing usually involves the use ofunderwater swimming gear andslingshot-like elastic poweredspearguns orcompressed gas powered pneumatic spearguns, which launch a tethered underwaterprojectile to strike the target fish. Specialised techniques and equipment have been developed for various types of aquatic environments and target fish. Spearfishing may be done usingfree-diving,snorkelling orscuba diving techniques.[55]
Abalone, lobster, sea urchins and various other marine invertebrates can be collected by hand or with the assistance of hand tools while diving.
Pearl hunting is the activity of recoveringpearls from wildmolluscs, usuallyoysters ormussels, in the sea or freshwater. Pearl hunting was prevalent in thePersian Gulf region andJapan for thousands of years. On thenorthern and north-western coast ofWestern Australia pearl diving began in the 1850s, where the term also covers diving fornacre or mother of pearl found in what were known aspearl shells. In most cases the pearl-bearing molluscs live at depths where they are not manually accessible from the surface. Historically the molluscs were retrieved byfreediving, When thestandard diving suit became available it was applied to pearl hunting.[56][57]
Sponge diving, is diving to collect soft natural sponges for human use as personal cleaning tools. It is one of the oldest known underwater diving activities, dating back to classical times, and was also originally a freediving activity which later made use of the standard diving helmet.[58]
Professional diving is done where the job is, but recreational divers have the freedom to choose where they dive, based on convenience, cost, their chosen underwater activities, and the characteristics of the environment at the available dive sites. Many recreational divers dive mainly in their home waters, but others will travel to sites where their preferences are more likely to be available.
Scuba diving tourism is the industry based on servicing the requirements ofrecreational divers at destinations other than where they live. It includes aspects of training, equipment sales, rental and service, guided experiences andenvironmental tourism.[50][51]
Motivations to travel for scuba diving are complex and may vary considerably during the diver's development and experience. Participation can vary from once off to multiple dedicated trips per year over several decades. The popular destinations fall into several groups, including tropical reefs, shipwrecks and cave systems, each frequented by its own group of enthusiasts, with some overlap. Temperate and inland open water reef sites are generally dived by people who live relatively nearby.[59][60]
Shark tourism is a form ofeco-tourism that allows people to dive with sharks in their natural environment. This benefits local shark populations by educating tourists and through funds raised by the shark tourism industry. People can get close to the sharks by freediving or scuba diving or by entering the water in aprotective cage for more aggressive species.
There are many recreational diving activities, and several equipment and environmental specialties which require skills additional to those provided by the entry level courses, These skills were originally developed by trial and error, but training programmes are offered by most diver training agencies for the convenience of the diver, and profit for the agency, or in the case of club oriented systems, for the overall benefit of the club community:
Freediving is a form of underwater diving that relies onbreath-holding until resurfacing rather than the use of breathing apparatus such asscuba gear. Besides the limits of breath-hold, immersion in water and exposure to high ambient pressure also have physiological effects that limit the depths and duration possible in freediving. Examples of freediving activities aretraditional fishing techniques, competitive and non-competitive freediving, competitive and non-competitivespearfishing and freedivingphotography,synchronised swimming,underwater football,underwater rugby,underwater hockey,underwater target shooting andsnorkeling. There are also a range of "competitiveapnea" disciplines; in which competitors attempt to attain great depths, times, or distances on a single breath:
The skills of underwater diving include some skills which are only needed in an emergency. These skills should be exercised sufficiently to ensure that if the emergency occurs, the diver is able to deal with it promptly and effectively. Skills practice can be done as part of a dive for other purposes, or in a dive dedicated to maintaining and developing the skills. Divers who do not dive sufficiently often to maintain basic skills may need to dorefresher courses orcheckout dives when returning to active diving. New skills may require dedicated practice to bring them up to a reliable standard.[73][74][75][76]
New equipment or a modification to equipment configuration may affect the diver's ability to operate the equipment or respond effectively to a problem. A common example is checking buoyancy control with a new diving suit, buoyancy compensator, cylinder configuration, or weighting system, or an unfamiliar model of rebreather. Buoyancy testing is done with the cylinders nearly empty, to ensure that the diver can maintain neutral buoyancy at the end of a dive during decompression, even if contingency use has depleted the reserve gas supplies. In many cases, testing new equipment does not require a special dive, as any problems will be noticed immediately, and either fixed or the dive can be safely aborted.[73][74][75][76]
Both foreseeable and not reasonably foreseeable emergencies can occur during a dive. Dealing with them in some way is necessary, and may involve the diver in self-rescue, the buddy, in assistance to the other buddy, or the safety diver orstand-by diver in assistance to the diver or divers in difficulty. Response to an emergency happening to someone else may lead topublic safety diving team involvement. Special circumstances like flooded cave rescues, entrapment in capsized vessels, and rescues from other disasters may involve larger groups.[73][74][75][76]
In-water recompression (IWR) is the emergency treatment ofdecompression sickness (DCS) by returning the diverunderwater to help the gas bubbles in the tissues, which are causing the symptoms, to resolve. It is a procedure that exposes the diver to significant risk which should be compared with the risk associated with the other available options. Some authorities recommend that it is only to be used when the time totravel to the nearestrecompression chamber is too long to save the victim's life, others take a more pragmatic approach, and accept that in some circumstances IWR is the best available option.[77][78] The risks may not be justified for case of mild symptoms likely to resolve spontaneously, or for cases where the diver is likely to be unsafe in the water, but in-water recompression may be justified in cases where severe outcomes are likely, if conducted by a competent and suitably equipped team.[79]
This is a table of underwater diving activities classified by occupational field and the diving modes usually associated with them. The mode may be dictated by the regulations or codes of practice governing the field of occupation.
| Diving activity name or description | Occupational classification | Diving modes generally used |
|---|---|---|
| aquarium maintenance in largepublic aquariums[80] | commercial,scientific[80] | Scuba, SSDE[80] |
| boat and ship inspection, cleaning and maintenance[81][6] | commercial,naval[81][6] | SSDE, occasionally scuba[81][12] |
| cave diving[21] | technical,recreational,scientific[21] | Scuba, occasionally SSDE[21] |
| civil engineering in harbours, water supply, and drainage systems[12] | commercial[12] | Almost exclusively SSDE[12] |
| offshore construction and maintenance in the crude oil and other industry[6] | commercial[6] | SSDE, ROV, occasionally atmospheric suit |
| demolition andsalvage ofshipwrecks[81] | commercial, naval[81] | SSDE, sometimes scuba, atmospheric suit or ROV[81] |
| professional diver training[81] | professional[81] | SSDE or scuba as appropriate[81] |
| recreational diver training[82][83] | professional,recreational[82][83] | Scuba, breathhold[82][83] |
| fish farm and otheraquaculture maintenance[80] | commercial[80] | Scuba, SSDE[80] |
| fishing/gathering, e.g. forabalones,crabs,lobsters,pearls,scallops,sea crayfish,sponges[84][85][56] | commercial, recreational[84][85][56] | Scuba, SSDE, breathhold[84][85][56] |
| frogman,manned torpedo[81] | military[81] | Scuba[81] |
| harbour clearance and maintenance[81] | commercial, military[81][12] | Almost exclusively SSDE[81][12] |
| media diving: making television programs,underwater videography,underwater photography etc.[21][6] | professional, recreational[21][6] | Scuba, ROV, occasionally SSDE[11] |
| mine clearance andbomb disposal, disposing ofunexploded ordnance[81] | military, naval[81] | Scuba, ROV, occasionally SSDE[81] |
| pleasure, leisure, sport[2] | recreational[2] | Scuba, breathhold, occasionally SSDE (Snuba)[2] |
| policing/security: diving to investigate or arrest unauthorized divers[81] | police diving, military, naval[81] | Scuba[81] |
| search and recovery diving[81] | commercial, public safety,police diving, military[81] | Scuba, SSDE, ROV |
| search and rescue diving[81] | police, naval, public service[81] | Scuba, occasionally SSDE[81] |
| spear fishing[86] | recreational(sometimes competitive),[86] occasionally professional, | Breathhold[86] |
| stealthyinfiltration[81] | military[81] | Scuba[81] |
| surveys and mapping[21][11] | scientific, recreational[21][11] | Scuba, SSDE[21][11] |
| scientific diving (marine biology,oceanography,hydrology,geology,palaeontology, diving physiology and medicine[21][6][11] | scientific[21][6][11] | Scuba, occasionally SSDE, atmospheric suit, ROV, AUV[21][11] |
| underwater archaeology (shipwrecks; harbors, and buildings)[21][11] | scientific, recreational[21][11] | Scuba, SSDE, ROV, occasionally atmospheric suit[21][11] |
| underwater inspections and surveys[81][6] | commercial, military[81][6] | SSDE, sometimes scuba, ROV[81] |
| underwater mineral extraction (gold, diamonds, oil)[87] | commercial | SSDE, including airline (Hookah) and saturation, ROV |
| competitive underwater sport, includingunderwater hockey,aquathlon,scuba orienteering,underwater rugby and others[86] | recreational[86] | Snorkel, breathhold and scuba[86] |
| underwater tour guiding[2] | professional, recreational[2] | Scuba[2] |
| underwater tourism[2] | recreational[2] | Scuba, occasionally Snuba[2] |
| underwater welding[6] | commercial[6] | Almost exclusively SSDE[12] |
Navigation by reference to terrain features, both natural and artificial, usually with the aid of an appropriate chart.
This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain.
