Diving procedures

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

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):
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*Selection of equipment – A diver is expected to be able select appropriate equipment and check it for fit and function.
* Preparation of equipment – Assembly and function checks of personal diving equipment
** Scuba assembly – Assembly and function check of the scuba set
*Site inspection and setup
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* Kit-up/dressing in the diver - Dressing into the diving suit, breathing apparatus, harness and accessories
**Pre-dive checks - Check that all necessary equipment is correctly fitted and functioning
* Entering the water - Use of an appropriate water entry technique
*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.
* Demand valve clearing – Expelling water from the interior of the demand valve.
* Descent – A generally consistent increase in depth until the operational depth is reached.
** Equalisation – Balancing pressures in air spaces with the ambient pressure.
*** Equalise dry suit squeeze – Injecting sufficient gas into the dry suit for comfort and insulation
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** Buoyancy control – Adjustment of the gas content in buoyancy compensator and dry suit to achieve appropriate buoyancy
** Trim control – Control of attitude in the water to suit the circumstances.
** Depth monitoring and control – Observation of current depth and ensuring it is appropriate
*Standard dive activities
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** Mask clearing and demisting – Discharge of water from the mask, and rinsing off condensation from the inner surface
** Maneuvering and mobility – Self-propulsion in the water column
** Monitoring decompression status – Keeping track of personal decompression obligation
** Monitoring breathing gas supply – Ensuring that the remaining gas supply is sufficient to complete the dive safely
** Balancing cylinder usage – ensuring that enough gas to safely finish the dive remains if any one cylinder loses all remaining gas.
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* Use of auxiliary equipment – Useful equipment, not needed on all dives.
**Towing a
**Deployment of a
*Planned diving activities - These are mostly considered underwater work, with a few exceptions and borderline cases.
** - This is generally considered to be a diving skill, not a work skill.
***Laying, marking, following and retrieving distance lines (guide lines). – Safety critical procedures in an overhead environment.
** – In professional diving these may be considered diving procedures or work procedures.
* Ascent – A generally consistent decrease in depth until the surface