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Naval diving

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Naval diving

"Hardhat diving" redirects here. Often, "hardhat diving" is used to specifically mean diving in the old-type Standard diving dress, or more generally Surface supplied diving.

Professional diving is a type of diving where the divers are paid for their work. There are several branches of professional diving, the most well known of which is probably commercial diving. Any person wishing to become a professional diver normally requires specific training that satisfies any regulatory agencies which have local authority, such as US Occupational Safety and Health Administration, United Kingdom Health and Safety Executive or South African Department of Labour. Due to the dangerous nature of some professional diving operations, specialized equipment such as an on-site hyperbaric chamber and diver-to-surface communication system is often required by law.

Procedural aspects

The primary distinction between professional and recreational diving is that the recreational diver is responsible primarily for his/her own actions and safety but may voluntarily accept limited responsibility for dive buddies, whereas the professional diver is part of a team of people with extensive responsibilities and obligations to each other and usually to an employer or client, and these responsibilities and obligations are formally defined in legislation, regulations, operations manuals, standing orders and compulsory or voluntary codes of practice. In many cases a statutory national occupational health and safety legislation constrains their activities.

Branches of professional diving

Commercial diving


Offshore diving

Main article: Commercial offshore diving

Offshore diving is the most well known branch of commercial diving, with divers working in support of the exploration and production sector of the oil and gas industry in places such as the Gulf of Mexico in the United States the North Sea in the United Kingdom and Norway and along the coast of Brazil. The work in this area of the industry includes maintenance of oil platforms and the building of underwater structures used in the production process.

Equipment used for offshore diving tends to be surface supplied equipment but this does vary depending on the nature of the work and location.[1] For instance Gulf of Mexico based divers may use wetsuits whilst North Sea divers need drysuits or even hot water suits due to the temperature of the water.[2]

Inland / onshore diving

Inland or onshore diving is very similar to offshore diving in terms of the nature of work and the equipment used, the work often being in support of land based civil engineering projects, with the majority of the work either underwater survey or engineering work. The types of dive sites this covers is varied, however, and divers can be found working in harbours and lakes, on hydroelectric dams, in rivers and around bridges and pontoons, with the bulk of this work being undertaken in freshwater. They are often required to inspect and repair outfalls which require at times up to 600 ft. plus penetrations, which require a multitude of safety requirements. Onshore divers typically can be at home every night and earn more per hour than their colleagues who work offshore. However, depth pay and minimum 12 hour shifts offshore must be taken into consideration.

The equipment used does depend on the nature of the work and location, but normally a mixture of SCUBA and surface-supplied diving equipment is used by divers and their employers.

HAZMAT diving

HAZMAT diving is widely regarded as the most dangerous branch of the commercial diving industry, employing highly skilled and experienced staff.

Typical work involves diving into raw sewage or dangerous chemicals, such as paper pulp, liquid cement, or oil sludge. This causes special requirements:[3]

  • The divers need to be vaccinated against diseases such as hepatitis and tetanus.
  • The dive company needs to have specialist plans in place for decontamination of the diver and equipment after a dive.
  • A way to recover the diver if something goes wrong.
  • The diver's weighting may need to be adjusted, if he is diving in a liquid whose density is much different from the density of water.

The main tasks a diver can be found to be doing include:

  • Essential maintenance of underwater valves and sluice gates.
  • Repairing damaged pipelines.
  • Pollution control work to contain, control, and clean up after a pollution incident.
  • Sampling activities, such as those performed by [2].
  • Some divers are required to dive into landfill sites to maintain the pumping equipment, vital in preventing landfill sites from filling up with rainwater and contaminating the water table.
  • Welding inside live sewers or working in septic tanks.
  • Miscellaneous repairs and finding lost objects.
  • Finding bodies.

Sewer diving is often considered the most dangerous of all the HAZMAT jobs due to the diseases contained in raw sewage and because syringes and glass find their way into the raw sewage, creating risks of contracting diseases.

Divers working in an environment harmful to their health will always wear a full drysuit with thick gloves which are attached directly to the suit. The helmet and boots will also attach directly to the drysuit, allowing the gloves, boots, suit and helmet to be pressured in order to prevent ingress of liquid should a puncture occur. Normally, to achieve this, a diver will use a free flow diving helmet which continually supplies enough air for the diver to breathe plus an additional amount to pressurize the suit. A free flow helmet has a much lower chance of leakage through the exhaust valve compared to a demand helmet where the exhaust valve is dormant during the inhalation stage of the diver breathing.

The drysuit will be made from a material resistant to whatever hazard the diver faces: normally the diver wears a vulcanised rubber drysuit, but occasionally a neoprene or tri-laminate suit is needed. Often, a diver will wear extra protection over their drysuit to decrease the chance of a puncture: leather, PVC, and nylon coveralls are used for this purpose.

In such diving, light is often very scarce and the water is usually very turbid, so most such divers rely on touch to guide them, and are usually connected via the umbilical to the surface. The umbilical serves as a supply of breathing gas, for communications, and as a lifeline to retrieve the diver in an emergency. It is also used as a guide to find the way back to the surface.

Nuclear diving

Nuclear diving is similar to HAZMAT diving; the difference is the exposure to radiation instead of a water borne contaminant. To this end, different precautions are required for nuclear diving, mainly, equipment which will not absorb radioactive contamination and pose a disposal problem after several dives.

Heat stress can also be a danger for the diver, in which case a cold water suit may be used: the cold water suit is a special canvas coverall which floods the outside of the diver's drysuit with chilled water, countering the dangerously high ambient water temperature. A dosimeter is used to ensure that the diver does not receive a dangerous dose of radiation during the dive, assisting in calculating the maximum length of the dive. In addition the dosimeter can also be used to find radiation hot spots, which can indicate areas in need of repair.

A dosimeter on the diver would never be used to check for radiation hot spots. The dosimeter on the diver is used to count his exposure and to alert him to overexposure. A separate device is used to search for hot spots. The diver sweeps the work area with a 3 foot long meter while a radiation tech up top reads the dose rates. While the sweep is happening the diver is relayed the dose rates for the areas he/she is sweeping.

Scientific diving

Scientific diving is the use of diving techniques by scientists to study underwater what would normally be studied by scientists on land. 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. Underwater archeology, marine biology and geology are examples of sciences pursued underwater. Some scientific diving is carried out by universities in support of undergraduate or postgraduate research programs.

Government bodies such as the United States Environmental Protection Agency and the UK Environment Agency carry out scientific diving to recover samples of water, marine organisms and sea, lake or riverbed material to examine for signs of pollution.

Equipment used varies widely in this field, but surface supplied equipment though quite uncommon in the UK is growing in popularity in the U.S. The short number of dives made by scientific divers in normally quite shallow water, and the UK governmental regulations that make surface supplied equipment cumbersome, when combined with a need for easy transportation make surface supplied gear uneconomic and undesirable for UK scientists to use.

The two standard references for Scientific Diving Operations are:

  • 18056894
  • Joiner James T. (ed), NOAA Diving Manual: Diving for Science and Technology, Fourth Edition, 2001, U.S.Department of Commerce, National Technical Information Service, (ISBN 0941332705)

USA

In the United States scientific diving is permitted by the OCEANS Volume:15, pp460-463.

To be able to avail itself of the Scientific Diving Exemption the institution under whose auspices the work is carried out must meet four tests:

  1. The Diving Control Board consisting of a majority of active scientific divers must have autonomous and absolute authority over the scientific diving program's operations.
  2. The purpose of all projects using scientific diving is the advancement of science; therefore, information and data resulting from the project are non-proprietary.
  3. The tasks of a scientific diver are those of an observer and data gatherer. Construction and trouble-shooting tasks traditionally associated with commercial diving are not included within scientific diving.
  4. Scientific divers, based on the nature of their activities, must use scientific expertise in studying the underwater environment and, therefore, are scientists or scientists in training.[6]

South Africa

In South Africa, scientific diving is considered a form of commercial diving and is within the scope of the Diving Regulations 2009 and the Code of Practice for Scientific Diving approved by the Chief Inspector of the department of Labour,[7] Under DR 2009 the Codes of Practice are guidance and not compulsory practice. They are provided as recommended good practice, and in theory need not be followed providing an acceptable level of safety is achieved in terms of the Occupational Health and Safety Act #85 of 1993. However, in this case the onus is on the diving contractor to ensure acceptable safety during the diving operation. The level of safety required is specified in the OHS act as "reasonably practicable" taking into account a number of factors, including cost effectiveness, availability of technology for mitigation and available knowledge of hazards. Use of the relatively flexible scientific code is restricted to clients which are registered as organisations engaged in either scientific research or higher education.

Australia

Although the first scientific diving expedition in Australia was carried out by Sir Maurice Yonge to the Great Barrier Reef in 1928, most scientific diving did not start until 1952 when the Commonwealth Scientific and Industrial Research Organisation began work to understand the pearl beds of northern Australia in 1957.[8]

Commercial divers worked under Australian Standard CZ18 "Work in Compressed Air" in 1972. This standard applied to caisson workers and divers so the underwater work was drafted into AS 2299 "Underwater Air Breathing Operations" in 1979. In 1987, a re-write of AS 2299 included scientific diving in the regulations even though the divers had been self-regulating under the Australian Marine Sciences Association (AMSA). At that time, the AMSA and the Australian Institute for Maritime Archaeology (AIMA) began a collaboration to draft a new standard for scientific diving.[8]

Media diving

Media Diving is a term used to describe divers engaged in underwater photography and underwater cinematography outside of normal recreational interests.[9] Media Diving is often carried out in support of television documentaries, such as the BBC series Planet Earth or Hollywood blockbusters, with feature films such as Titanic and The Perfect Storm featuring underwater photography or footage. Media divers are normally highly trained camera operators who use diving as a method to reach their workplace, although some underwater photographers may 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, but rebreathers 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 at hand.[10]

Military and naval diving

Main articles: Army engineer diver, Clearance Diver and Frogman

Military diving covers all types of diving carried out by military personnel.[11] There are a number of different specialisations for a military diver to choose, some depend on which branch of the military they've joined or where the military needs more divers. Typical offensive activities include underwater demolition, infiltration and sabotage, this being the type of work elite regiments such as the UK Special Boat Service or the USA Navy SEALs carry out. Defensive activities are centered around countering the threat of enemy special forces and enemy anti-shipping measures, and typically involve defusing mines, searching for explosive devices attached to the hulls of ships, and locating enemy frogmen in the water.

Military divers need equipment which hides their position and prevents explosives from being set-off, and to this end, they use rebreathers which produce few or no bubbles on the surface, and which contain no magnetic components. This continues down to the design of their diving suit, which will normally have a non-magnetic zipper, and the face-mask may be fitted with special anti-reflective glass. Some navies have gone further and given their divers special contact lenses instead of large face-masks to cut down on the risk of a reflection.

Naval diving is the military term for commercial diving, and is drastically different from military diving. Naval divers work to support maintenance and repair operations on ships and military installations. Their equipment is derived from commercially available equipment, with the US Navy using versions of the Kirby Morgan helmets and full-face masks amongst other equipment. Typical tasks include:

  • boat and ship inspection, cleaning and maintenance
  • demolition of ship wreck and unexploded ordnance
  • ship, submarine, downed aircraft, and other military hardware salvage or recovery
  • underwater mine clearance
  • investigating unidentified submerged divers

The United States Army has its own organic assets. These are the Army engineer divers.

Experimental diving, is conducted by the US Navy's Experimental Diving Unit (NEDU) and involves meeting military needs through the research and development of diving practices and diving equipment, testing new types equipment and finding new and safer ways to perform dives and related activities. The US NEDU was responsible for much of the early experimental diving work to calculate decompression tables and has since worked on such developments as heated diving suits powered by radioactive isotopes and mixed gas diving equipment, while the British equivalent (The Admiralty Experimental Diving Unit) perfected the Mark 10 submarine escape suits utilized by both the Royal Navy and the US Navy.[12][13]

Police diving

Main article: Police diving

Police divers are normally police officers who have been trained in the use of diving techniques to recover evidence and occasionally bodies from rivers, canals and the sea.[14] They may also be employed in searching shipping for contraband substances fitted to the outside of hulls to avoid detection. The equipment they use depends on requirements, but the requirement for communications at some sites does often require the use of full-face masks with communication equipment, either with SCUBA or surface supplied equipment.

Diving instructors

Instructors for each of the above modes of diving are highly qualified individuals operating under the auspices of a governmental agency. Standards for instruction are authorized by agencies to ensure safety.

Recreational dive instructors differ from other types of professional divers as they normally don't require a professional level qualification, but a relevant recreational qualification from a recognised training agency such as GUE, SDI, TDI, NAUI, PADI, SSI, ANDI or BSAC, which permits them to teach. Dive instructors teach a wide variety of skills from entry-level diver training for beginners, to diver rescue for intermediate level divers and technical diving for more experienced divers. They often operate from dedicated dive centres at coastal sites or through hotels in popular holiday resorts or simply from local swimming pools. Initial training is carried out mainly on conventional SCUBA equipment[15][16][17] but with the increasing use of rebreathers, their use is also taught.[18][19][20][21][22][23]Not all dive instructors are professionals; many instructors are amateurs with careers outside the diving industry.

Commercial diving instructors normally require professional diving qualifications. They typically teach trainee commercial divers how to operate types of diving equipment and typical underwater tools they will use in the course of their work. Commercial diving instructors will use similar equipment to commercial divers in the course of their work.

Aquarium Diving

Aquarium Divers normally hold some form of professional qualification, either as a Diving Instructor or in the UK a HSE Part 4 qualification. The larger aquariums can have considerable size and depth, in the UK 35 by 25 metres and 5 metres deep with 3.8 million litres of water. The jobs are varied but are centred around the maintenance of the tank and livestock and public entertainment. They include:

  • Feeding of the livestock
  • Tank cleaning
  • Shows
  • Taking members of the public into the tank

Equipment


Diving suit

Main article: Diving suit

Depending on the water temperature, depth and duration of the planned dive, the diver will either use a wetsuit, drysuit or hot water suit. A wetsuit provides thermal insulation by layers of foam neoprene but the diver gets wet. Hot water diving suits are similar to a wetsuit but are flooded with warm water from a surface water heater that is then pumped to the diver via an umbilical. A drysuit is another method of insulation, operating by keeping the diver dry under the suit, and relies on either the suit material or the air trapped in thermal undergarments to insulate the diver, and also provides better isolation from environmental contamination.

Certain applications require a specific type of dive suit; long dives into deep, cold water normally require a hot water suit or drysuit, whilst diving into potentially contaminated environments requires a drysuit, dryhood, and drygloves at a minimum, thereby keeping the diver completely isolated from the diving environment.[3][24][25]

Breathing apparatus

A number of factors dictate the type of breathing apparatus used by the diver.[11] Typical considerations include the length of the dive, water contamination, space constraints and vehicle access for support vehicles.[3] Some disciplines will very rarely use surface supplied diving, such as scientific divers or military clearance divers, whilst commercial divers will rarely use SCUBA equipment.

Scuba

Main article: Scuba diving

SCUBA equipment is not commonly used in civilian commercial diving, but is often employed by scientific, media and military divers, sometimes as specialized equipment such as rebreathers, which are closed circuit SCUBA equipment that recycles breathing gas instead of releasing it into the water. It is the "re-breathing" of gas that makes rebreathers ideal for long duration dives, efficient decompression when the gas mix is adjustable, and for the observation of animals in the wild due to the lack of noisy bubbles. These characteristics also make rebreathers ideal for military use, such as when military divers are engaged in covert action or when performing mine clearance where bubbles could potentially set off an explosion.

Open circuit scuba equipments are occasionally used by commercial divers working on sites where surface supplied equipment is unsuitable, such as around raised structures like a water tower, or in remote locations where it is necessary to carry equipment to the dive site. Normally, for comfort and for practicality, a full face mask such as those manufactured by Kirby Morgan will be used to allow torches and video cameras to be mounted onto the mask. The benefit of full-face masks is that they can normally be used with surface supplied equipment as well, removing the need for the diver or the company to have two sets of expensive equipment.[26][27]

Surface supplied

This is, perhaps, the most common type of equipment used in professional diving, and the one most recognised by the public, made familiar through films such as The Abyss.Surface Supplied equipment can be used with full face masks or diving helmets.[26] Helmets are normally to be found fitted with diver to surface communication equipment, and often with light sources and video equipment. The decision between wearing a full-face mask or a full diving helmet comes down to job requirements and personal preference, however the impact protection and warmth offered by a full diving helmet makes it popular for underwater construction sites and cold water work.

Breathing gas for the diver is piped down from the surface, through a long, flexible hose, called an umbilical.[2][28] In addition to breathing gas, the umbilical may have additional hoses and cables for such things as communications equipment, a pneumofathometer for measuring depth, or hot water should the diver be using a hot water suit. The umbilical must be strong enough to support the diver's weight, with a significant safety margin, because it may be used by surface personnel to pull the diver out of the water. The diver's breathing gas can is pumped down from either high pressure tanks or through a gas compressor.

If the diver is to be working at extreme depths for a long period, the diver may live in a special underwater habitat called a diving chamber.[2] This type of surface supplied diving is known as saturation diving.[2] The same technique for supplying breathing gas as regular surface supplied diving is used, with the diving bell receiving breathing gas and electricity from a diving support vessel on the surface.[2] Due to the often extreme depths the diver is working at, specialised helium-based breathing gas mixtures are often used to prevent both nitrogen narcosis and oxygen toxicity which occurs at these extreme depths.[29]

Training and registration

Regional requirements

Canada

The Diver Certification Board of Canada[30] certifies occupational divers, accredits schools which train occupational divers.

The Diver Certification Board of Canada (DCBC) is a federally incorporated not-for-profit body which was originally set up to replace the offshore diver certification regime of the National Energy Board and the offshore petroleum boards. DCBC is the only national body which certifies offshore and inshore commercial divers in Canada.

The DCBC offers certification to commercial divers and supervisors who can demonstrate that they have sufficient training and experience to enable them to meet the competency requirements of the appropriate section of the Canadian Standards Association (CSA) Competency Standard for Diving Operations (CSA Standard Z275.4).

Certificates issued by the DCBC are recognized by Australia (ADAS), France, Norway, South Africa, the United Kingdom (HSE) and the International Marine Contractors Association (IMCA).

The Diver Certification Board of Canada accredits commercial diver training organizations which train to the competency levels described in CSA Standard Z275.4. Accredited commercial diver training organizations can also assess the competency of experienced commercial divers who were not trained at an accredited school.

United Kingdom

In the UK, any person diving at work is required to hold a relevant qualification approved by the Health and Safety Executive (HSE). In the UK, diving schools work towards a standard HSE approved qualification, whilst divers who have trained overseas may find their existing qualifications meet the necessary HSE standards, if not, additional training may be required. HSE approved qualifications are well known around the world and due to the stringent requirements of HSE qualifications, most diving qualifications around the world are designed to meet HSE standards, allowing any trained diver to work in the UK, an important location due to the North Sea oil industry. The stringent requirements of the HSE qualifications make then a common requirement around the world for employers looking for new staff.

There are several different HSE qualifications, each focusing on a different type of equipment or type of diving activity, for instance the HSE Scuba qualification allows the holder to use only SCUBA equipment. Training usually takes place at a residential school, with courses taking anything between 9 and 13 weeks although divers with existing qualifications, such as former military divers can take courses which build on their existing knowledge and experience. During training, divers will be taught how to use common types of diving equipment (nearly every school trains divers to use the Kirby Morgan equipment) and how to carry out underwater construction techniques such as welding and cutting.

In addition to physical training, there is a large amount of classroom work, with divers being trained subjects such as basic gas laws and decompression tables. First Aid courses are normally also a requirement for trainee divers, with the emphasis placed on dealing with decompression and other diving related injuries.

South Africa

In South Africa the Department of Labour regulates the activities of people who dive as part of their employment, except for those involved in diving connected to minerals and energy, who are nominally controlled by the Department of Minerals and Energy. Military diving is also officially within the jurisdiction of the Department of Labour, but provided the diving is conducted within the requirements of SA Naval Operations Publication 96 it is deemed to comply with the Diving Regulations of the Occupational Health and Safety Act 1993.

All commercial diver training is within the scope of the Diving Regulations, but recreational diver training and dive leading (divemasters) are specifically excluded from the regulations, though still subject to general provisions of the Occupational Health and Safety Act [7]

Commercial divers are registered with the Department of Labour after completing their training and assessment at registered commercial diving schools. The standard of training is officially specified in the Commercial Diver Training Standards for each class of diver, but the precise definitions for many of the specified items is unclear. However this is not unlike the standards for training in several other countries, as the SA standards are remarkably similar to the standards published by the International Diver Recognition Forum (IDRF) of which the SA Department of Labour is a member.

International commercial diving co-ordination and regulatory associations and organisations

International Marine Contractors Association (IMCA)

The International Marine Contractors Association (IMCA) is the international trade association representing offshore, marine, and underwater engineering companies. Contractors, suppliers, training establishments, personnel agencies and non-voting corresponding (oil companies, governmental and regulatory bodies) can become members in one or more of the four divisions (Diving, Marine, Offshore Survey, Remote Systems & ROV).

International Diving Schools Association (IDSA)

Main article: International Diving Schools Association

IDSA[31] was formed in 1982 with the primary purpose of developing common international standards for commercial diver training

The Association is concerned with offshore, inshore and inland commercial diving and some specialist non-diving qualifications such as diving supervisors, diving medical technicians and life support technicians. It has published international diver training standards[32] based on the consensus opinion of members which provide a basic standard of comparison for commercial diver training standards, with the stated intention of:-

  • Improving safety
  • Providing contractors with a direct input to the diver training syllabus
  • Enabling contractors to bid across national borders on a more even playing field
  • Improving diver quality
  • Providing divers with greater job opportunities

IDSA provides a Table of Equivalence of various national commercial diver training standards.[33]

International Diving Regulators Forum (IDRF)

Main article: International Diving Regulators Forum

The International Diving Regulators Forum (IDRF) confirmed its principals and purpose at their meeting in London in September 2009. The statement of principals and purpose states “The forum has agreed to work together towards mutual recognition to identify and implement best practice in diver training and assessment with the objective of harmonising cross-border diver training outside Europe.”

Members of the IDRF include ADAS (Australia), DCBC (Canada), HSE (UK), PSA (Norway), and the Secretariat General to the Sea Progess Committee (France).

See also

For scientific and archaeological applications for which diving is needed see:

For other diving activities

References

External links

  • USA Government Regulations for Commercial Diving (federal code)
  • UK Health and Safety Executive Website (UK Government)
  • Australia Diver Accreditation Scheme Website (Australian Government)
  • Diving Diseases Research Centre
  • Sea Research Society
  • Offshore Diver Diver's Forums, Divers Galleries, Articles, Sea Stories, Extensive Reference Section. One of the oldest and largest.
  • Longstreath Another of the oldest and largest commercial diving sites on the internet and, in fact, the oldest.
  • History of Commercial Diving
  • Brief history and overview of Commercial Diving
  • Diving Heritage Life of a nuclear diver
  • Becoming a Commercial Diver - a report
  • History of Diving Museum Home of the Association of Diving Contractors, International (ADCI) Commercial Diving Hall of Fame Monument
  • List of commercial diving organizations

Construction diving articles

  • Selecting a welding machine for wet welding and underwater cutting, Offshore Diver, July 15, 2010

Hazmat diving articles

  • Diver enjoys doing the dirty work, Robbie Dingeman, Honolulu Advertiser, March 12, 2004
  • Divers to give deep tunnel a much-needed deep cleaning, Steve Schultze - Marie Rohde, Milwaukee Journal Sentinel, Nov 29, 2004
  • Deep-Slime Divers Keep Vast and Smelly Sewers Flowing, Mary Jordan, Washington Post, August 30, 2004
  • Getting down and dirty in México City, Marla Dickerson, Los Angeles Times
  • Mexican sewage divers submerge in murky world, Monica Medel - Reuters, San Diego Union-Tribune, December 19, 2006
  • Sewage divers keep city's bowels in working order, Jo Tuckman, Sydney Morning Herald, July 17, 2004

Nuclear diving articles

  • , March 27, 2012


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