Standardised methods of doing things that are known to work effectively and acceptably safely
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 and maintenance 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 both 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 by law to provide any evidence of competence.
Routine diving procedures
Checking equipment function before use
Fitting a lightweight demand helmet
Backward roll entry
stride entry from a low platform
Descent on a diving stage
Hand signal communication during a training exercise
Checking the chamber BIBS
Monitoring the decompression chamber
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.
After-dive maintenance and storage of equipment, debriefing, and logging the dive are also procedural parts of the normal diving operation.
Clearing a flooded demand valve is both a routine procedure and an emergency procedure. It is an emergency procedure because if the DV is not cleared, the diver could aspirate water and choke, but it can easily happen, and will happen when a diver switches to a different gas supply delivered through a different DV, and there are two easy ways to deal with it, so it should not be a problem on a dive which runs according to plan.
Routine scuba diving procedures (order may vary slightly, and some are also relevant to surface supplied diving, though details may vary):
Dive planning – The process of planning an underwater diving operation
Selection of equipment – A diver is expected to be able select appropriate equipment and check it for fit and function.
Surface checks - Final function checks and reports before descent.
Breathing from the demand valve – The pattern of breathing can affect work of breathing and effective dead space, both of which must be limited, and preferably minimised. Mouthpieces must seal against the lips when used to prevent aspiration of water.
Locking out of and into the bell – Equalising the interior pressure with the water, opening the lock and entering the water, followed by checking the bell and proceeding to the worksite. Later returning to the bell, exiting the water and closing the lock to achieve a pressure seal.
Saturation decompression – Decompressing back to normal surface pressure after a dive where all tissue compartments have saturated with the inert gas in the breathing mixture.
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.
Manage a broken faceplate – Unrestricted flooding of the helmet is a life-threatening emergency. The dive will be terminated. Flooding can be minimised by positioning the leak as low as possible and opening the free-flow valve.
Dynamic positioning alarm and runout response - Dynamic positioning failure puts the divers at risk of being dragged by their unbilicals without warning, with a risk of snagging and rupture. They will return to the bell as a matter of urgency. The bellman will take up slack to help avoid snagging.
Bell gas panel operation – The bell gas panel is used to switch to on-board gas supply if the surface supply is compromised.
Main lifting wire/winch failure – Alternative lifting possibilities include the clump weight winch, other hoisting equipment on the platform, and if rated for lifting, the bell umbilical. Through-water transfer at depth to another bell may be possible.
Demonstration of oxygen administration for diver first aid
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.
Recovery of diver to the bell – Getting an incapacitated diver back to the bell where a relatively secure breathing gas supply is available and some first aid is possible, and the first stage of recovery to the surface.
Lost bell procedures – Locating and lifting a closed bell when the lifting cables and umbilical have been severed
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^ abRanapurwala, 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. PMID26534948.
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