Diving procedures are standardised methods of doing things that are commonly useful while diving that are known to work effectively and acceptably safely.
Due to the inherent risks of the environment and the necessity to operate the equipment correctly, both under normal conditions and during incidents where failure to respond appropriately and quickly can have fatal consequences, a set of standard procedures are used in preparation of the equipment, preparation to dive, during the dive if all goes according to plan, after the dive, and in the event of a reasonably foreseeable contingency. Standard procedures are not necessarily the only courses of action that produce a satisfactory outcome, but they are generally those procedures that experiment and experience show to work well and reliably in response to given circumstances. All formal diver training is based on the learning of standard skills and procedures, and in many cases the over-learning of the skills until the procedures can be performed without hesitation even when distracting circumstances exist. Where reasonably practicable, checklists may be used to ensure that preparatory procedures are carried out in the correct sequence and that no steps are inadvertently omitted.
Some procedures are common to all manned modes of diving, but most are specific to the mode of diving and many are specific to the equipment in use. Diving procedures are those directly relevant to diving safety and efficiency, but do not include task specific skills. Standard procedures are particularly helpful where communication is by hand or rope signal – the hand and line signals are examples of standard procedures themselves – as the communicating parties have a better idea of what the other is likely to do in response. Where voice communication is available, standardised communications protocol reduces the time needed to convey necessary information and the error rate in transmission.
Diving procedures generally involve the correct application of the appropriate diving skills in response to the current circumstances, and range from selecting and testing equipment to suit the diver and the dive plan, to the rescue of oneself or another diver in a life-threatening emergency. In many cases, what might be a life threatening emergency to an untrained or inadequately skilled diver, is a mere annoyance and minor distraction to a skilled diver who applies the correct procedure without hesitation. Professional diving operations tend to adhere more rigidly to standard operating procedures than recreational divers, who are not legally or contractually obliged to follow them, but the prevalence of diving accidents is known to be strongly correlated to human error, which is more common in divers with less training and experience. The Doing It Right philosophy of technical diving is strongly supportive of common standard procedures for all members of a dive team, and prescribe the procedures and equipment configuration that may affect procedures to the members of their organisations.
The terms diving skills and diving procedures are largely interchangeable, but a procedure may require the ordered application of several skills, and is a broader term. A procedure may also conditionally branch or require repeated applications of a skill, depending on circumstances. Diver training is structured around the learning and practice of standard procedures until the diver is assessed as competent to apply them reliably in reasonably foreseeable circumstances, and the certification issued limits the diver to environments and equipment that are compatible with their training and assessed skill levels. The teaching and assessment of diving skills and procedures is often restricted to registered instructors, who have been assessed as competent to teach and assess those skills by the certification or registration agency, who take the responsibility of declaring the diver competent against their assessment criteria. The teaching and assessment of other task oriented skills does not generally require a diving instructor.
There is considerable difference in the diving procedures of professional divers, where a diving team with formally appointed members in specific roles and with recognised competence is required by law, and recreational diving, where in most jurisdictions the diver is not constrained by specific laws, and in many cases is not required to provide any evidence of competence.
Routine diving procedures
These are the procedures that the diver uses during the course of a planned dive, where everything goes to plan, and there are no contingencies. Consequently experienced divers tend to become expert in these procedures due to adequate practice. Some procedures may seldom be needed, or only be relevant to specific equipment, which is not often used, so refresher exercises are frequently required before dives using unfamiliar equipment, unusual tasks or unfamiliar conditions are expected.
Dive planning, the pre-dive briefing. and selection, inspection, preparation and pre-dive checking of diving equipment, may be considered diving procedures, as they are essential parts of the normal diving operation, though they are done before entering the water.
In-water procedures in this grouping include entry to the water, surface swimming, descent, buoyancy and trim control, equalisation of pressure in air spaces, maneuvering in midwater and at the bottom, monitoring the dive profile, gas supply and decompression obligations, normal ascent and exit from the water. For some divers, gas switching, deployment of a decompression buoy and staged decompression may be added, or navigation under an overhead. Communications procedures depend on equipment and mode of diving, but are also in this group.
Routine scuba diving procedures (order may vary slightly):
- Dive planning – The process of planning an underwater diving operation
- Selection of equipment
- Preparation of equipment
- Site inspection and setup
- Pre-dive briefing – Meeting of the dive team to discuss details before the diving operation
- Kit-up/dressing in the diver
- Entering the water
- Surface checks
- Breathing from the demand valve
- Descent – A generally consistent increase in depth until the operational depth is reached.
- Standard dive activities
- Communications – Methods used by underwater divers to communicate
- Mask clearing and demisting
- Maneuvering and mobility
- Monitoring decompression status
- Monitoring breathing gas supply
- Balancing cylinder usage – ensuring that enough gas to safely finish the dive remains if any one cylinder loses all remaining gas.
- Rebreather diving – Underwater diving using self contained breathing gas recycling apparatus
- Use of auxiliary equipment
- Planned diving activities - These are mostly considered underwater work, with a few exceptions and borderline cases.
- Navigation – Underwater navigation by scuba divers - This is generally considered to be a diving skill, not a work skill.
- Underwater searches – Techniques for finding underwater targets - In professional diving these may be considered diving procedures or work procedures.
- Ascent – A generally consistent decrease in depth until the surface is reached.
- Decompression – The reduction in ambient pressure experienced during ascent from depth, and the process of elimination of dissolved inert gases from the diver's body tissues.
- No-stop diving – Diving which limits tissue inert gas concentrations to those which allow acceptably safe surfacing without decompression stops
- Repetitive diving – Diving again while some tissues have not reached equilibrium with surface saturation.
- Staged decompression - Decompression at fixed depth intervals, a practise which allows use of decompression tables.
- Gas switching - Changing between breathing gases during a dive to a gas suited to the current depth, to limit oxygen toxicity or nitrogen narcosis, or to accelerate decompression
- Management of multiple cylinders – Managing additional cylinders with different gas mixtures.
- Accelerated decompression – Use of oxygen enriched gas mixtures to accelerate inert gas elimination.
- Oxygen decompression – Use of pure oxygen to accelerate inert gas elimination.
- Monitoring decompression using a planned schedule, depth measurement and elapsed time.
- Monitoring decompression using a dive computer
- Surfacing – The final stage of ascent
- Return to exit point – Getting from the position of surfacing to a place where the diver can safely exit the water, usually by finning at the surface
- Exit from water
- Log dive – Recording specific details about the dive in a logbook (paper or electronic database)
- Clean, inspect and store equipment
- Pack up site
Routine Surface-supplied diving procedures:
- Preparing the surface supplied diving equipment
- Dressing in the diver
- Pre-dive checks
- Demisting the faceplate – getting rid of condensation droplets on the inner face of the viewport to improve vision.
- Clearing a flooded helmet or full-face mask – Expelling water which found its way into the interior space and can hinder safe breathing.
- Adjusting the breathing resistance – adjusting inhalation and exhalation pressure differences to reduce the work of breathing of a demand regulator.
- Voice communication – Use of standard voice protocols to facilitate accurate and reliable communication.
- Rope signals – Use of standard code of pull signals transmitted via the lifeline or umbilical when voice is not available
- Umbilical management – Keeping slack, twists, and snags from the route of the umbilical to the diver
- In-water decompression – Fully decompressing in the water
- Surface decompression – Leaving the water before fully decompressed and recompressing in a chamber to finish the decompression in relative comfort.
- Preparation of the bell
- Descent and ascent
- Bell integrity check at the bottom
- Monitoring at the bell
- Umbilical management
- In-water tending
- Securing the bell for ascent
- Locking out of and into the bell
- Tending the working diver
- Transfer under pressure
- Operation of the closed bell gas panel
- Saturation decompression
These are the procedures that the diver is expected to be able to follow in the event of a reasonably foreseeable contingency. Some occur quite often such as the loss of grip on the mouthpiece in scuba diving, and are therefore usually well practiced. Others, like bailing out to emergency gas supply, should never happen if the equipment does not fail and the dive is carried out according to a good plan, and must be practiced as an exercise to maintain the skill or as part of pre-dive checks to ensure that the equipment is functioning correctly, as failure to perform correctly could be fatal.
Emergency procedures are procedures to recover from a contingency that could be life-threatening if not responded to promptly and correctly. Some are trivially easy for a skilled diver. They include regulator recovery, clearing a flooded mask or helmet, bailout to emergency gas supply, emergency swimming ascent (for scuba), bell abandonment, shedding of weights (scuba), breathing off the pneumofathometer hose (SSDE), and switching over to onboard gas (bell diving). In cave or wreck diving, finding a lost guideline and finding the other end of a broken line are also emergency procedures.
- Regulator clearing
- Regulator recovery
- Stop freeflow
- Switch and isolate regulator in case of freeze
- Stop and correct runaway dry suit inflation
- Stop and correct runaway buoyancy compensator inflation
- Manage dry suit flooding
- Recovery from accidental inversion in dry suit
- Follow guideline in silt-out
- Find lost guideline
- Cross break in guideline
- Emergency ascents
- Lost mask ascent
- Lost buoyancy ascent
- Omitted decompression procedure
- Assisted ascents – Ascents where the diver in distress is assisted by another diver
- Independent emergency ascents – Where the diver takes independent action and has no assistance
- Ascent while breathing from the buoyancy compensator
- Buoyant ascent
- Lost weights ascent with flare
- Controlled buoyant emergency ascent
- Emergency swimming ascents
- Free ascent
- Controlled emergency swimming ascent
- Cut free from entanglement
- Ditch weights to establish buoyancy
- Standardised emergency procedures used with manifolded twins
- Therapeutic recompression
- Mask or helmet clearing
- Bailout to scuba
- Bailout to pneumo hose
- Switch to bell onboard gas
- Abandon wet bell
- Respond to heating water malfunction
- Respond to dry suit flood
- Respond to suit blowup
- Respond to buoyancy compensator blowup
- Respond to voice communications failure
- Free a snagged umbilical
- Manage vomiting in the helmet
- Manage a broken faceplate
- Dynamic positioning alarm and runout response
- Bell gas panel operation
- Bell abandonment
- Surface gas supply failure
- Voice communications failure
- Light and gas signals for surface supplied dives
- Contaminated surface gas supply
Closed bell emergency procedures:
- Bell umbilical failure
- Dynamic positioning alarm and runout response
- Main lifting wire/winch failure
- Loss of bell internal pressure
These are procedures that the professional standby diver must execute when deployed to go to the assistance of the working diver in an emergency, or the buddy or dive-team member in a recreational or technical dive should use if another member of the team is unable to manage an emergency themselves. They are also emergency procedures, but for another person's benefit. It is fairly common for a diver never to need to apply one of these procedures for real, and they too should be practiced to maintain skill levels. Professional diving organisations typically require periodical emergency exercises as specified in their operations manual to maintain these skills.
Rescue procedures include following the umbilical or lifeline to the distressed diver, providing emergency breathing gas, recovering the casualty to the bell or surface, releasing a snagged umbilical, umbilical changeout at depth, providing the supervisor with continuous updates. Rescues are generally done in unexpected circumstances, and seldom follow the text-book example, so the rescue diver often has to modify the learned response to suit reality.
- Locating the casualty underwater
- Providing emergency gas
- Freeing the trapped casualty
- Managing a convulsing casualty
- Bringing the casualty to the surface
- Controlled buoyant lift
- Making the casualty buoyant on the surface
- Carrying out artificial ventilation in the water
- Towing the casualty
- Assisting a trapped diver
- Rescue of an incapacitated diver
- Rescue of an unconscious diver
- Umbilical changeout
- Rescue of the working diver
- Bell abandonment, or Rescue of divers from a disabled bell
- Recovery of diver to the bell
- Lost bell procedures
- Larn, Richard; Whistler, Rex (1993). "8: Scuba Diving Procedures". Commercial Diving Manual (3rd ed.). Newton Abbott, UK: David and Charles. ISBN 0-7153-0100-4.
- Ranapurwala, Shabbar I; Denoble, Petar J; Poole, Charles; Kucera, Kristen L; Marshall, Stephen W; Wing, Steve (2016). "The effect of using a pre-dive checklist on the incidence of diving mishaps in recreational scuba diving: a cluster-randomized trial". International Journal of Epidemiology. Oxford University Press on behalf of the International Epidemiological Association. 45 (1): 223–231. doi:10.1093/ije/dyv292.
- Ranapurwala, Shabbar I. (Winter 2013). "Checklists". Divers Alert Network. Retrieved 3 October 2018.
- International consensus standards for commercial diving and underwater operations (Sixth (R6.2) ed.). Houston, Texas: Association of Diving Contractors International, Inc. 2016.
- Class IV Training Standard (Revision 5 ed.). South African Department of Labour. October 2007.
- Class II Training Standard (Revision 5 ed.). South African Department of Labour. October 2007.
- Bevan, John, ed. (2005). "Section 6.2 Diver Voice Communications". The Professional Divers's Handbook (second ed.). Gosport, Hampshire: Submex Ltd. pp. 250–251. ISBN 978-0-9508242-6-0.
- Jablonski, Jarrod (2006). "4: DIR Philosophy". Doing It Right: The Fundamentals of Better Diving. High Springs, Florida: Global Underwater Explorers. pp. 53–54. ISBN 0-9713267-0-3.
- Class III Training Standard (Revision 5 ed.). South African Department of Labour. October 2007.