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Under Stress

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Some divers handle it better than others, but underwater we all deal with it for better or worse

Text by Bret Gilliam

The following continues a discussion on diving and stress that appears in the current issue of DIVER Magazine, Volume 37 Number 8, now available on newsstands.

This leads into the current debate about what equipment is necessary for deep diving. Many experts do have some concerns about trends that exhibit a fascination for equipment-intensive outfitting far in excess of the practical requirements of the dive.  At some plateau, the point of diminishing returns is reached: is carrying 300 cubic feet of gas effective if the performance detriment by the sheer weight/size/drag of such gear requires the additional gas supply?  In 1990, I deliberately chose a single cylinder (115 cu. ft.) and regulator package to lessen my equipment load on my record 452-foot (138m) compressed air dive.  With proper breathing techniques, etc., I was able to comfortably complete the dive on this reduced rig.  Some would argue that redundancy is a requirement at such extreme depths but with DIN fittings I was not concerned with a regulator failure at the valve.  Therefore, the physical stress and distraction of extra equipment to me was not justified.  I wanted to carry enough gas with me to do the dive, obviously, but the single cylinder provided that for me and I was far more comfortable in the water. This was over 21 years ago and today an abundance of alternative gear options exist.

Logically, deep divers must carry the gas volumes necessary to complete the dive plan with an adequate safety margin.  Extended decompression in colder water will dictate larger gas storage carried by the diver but we caution readers to carefully weigh the equipment stress load with operational requirements of the dive site. There will always be debate on what equipment is necessary but a perspective on what is realistically matched to the dive plan must be encouraged.

An experienced diver dresses for the occasion as it were. A tuxedo is not required for a backyard barbecue. Veteran divers who have access to the most advanced gear will not hesitate to simplify a gear set when conditions allow. My record dive to 452 feet (138m) was focused on a specific goal and was of limited duration. On air at such extreme depths I balanced my gas volume needs, based on long experience, against performance ideals dictated by a stripped-down and low-drag configuration gear set. In contrast, Sheck Exley’s record mixed gas dive to 881 feet (268.5m) had totally different requirements due to cold water, multiple gas switches, extreme depth and drastically extended decompression time. Both dives were extremely hazardous and conducted solo, but both were successful, in part, by balancing equipment packages to the precise operational requirement.

Divers should know – precisely – their personal gas consumption rates at a range of depths and in different dive situations. Likewise, a consideration of their thermal comfort and suit needs must be plugged into the equipment equation. For Caribbean divers conducting multi-level drop-off wall excursions to depths to 200 fsw (61m), a single BCD is probably adequate with an oversized single cylinder and a regulator with DIN fittings. Some will want the redundancy of a Y-valve for regulator back up. That’s okay. We’re still dealing with a manageable gear package. The same dive conducted on a northeast wreck will quite obviously call for an expanded gear set including doubles, dry suits, etc. But let’s always keep in mind the common sense rule of equipment stress: match your gear set closely to your operation.

Ego threat stress is significant as well in our dive planning.  Smith (1979) notes, “An individual can be effectively destroyed by tearing down self-esteem, pride or ego. . .” The overextension of capabilities by personal challenge or peer group pressure is a leading contributory factor to deep diving accidents.  Individuals must seek at all times to dive within their limitations.  One veteran diver relates the 1988 case of an experienced northeast coast wreck diver who elected to sit out the last dive of the day as conditions worsened.  Unconcerned by peer reaction (if any), he was complimented for his good judgment in knowing when to quit.

We must not let perceived ego threats intrude on our good judgment.  Divers should not encourage others to participate in deep diving activities that make them uncomfortable.  The emotionally mature diver can abstain from diving in any situation without concern for a wounded ego. Smith (1979) puts it best: “The truly mature person can do this even when others may extend themselves further into the situation because of either their superior ability or their own foolishness.  The threat to one’s ego when one must back away from a challenge can be quite stressful, and tolerance to this stress is important in diving . . . a diver who is incompetent and knows it may be stressful.  An incompetent diver may also be stressful to other divers who know about the incompetency.  A diver may even stress companions into death by threatening their ego through constantly challenging them to test their limits to save their pride.”

Effects of Stress
Even a passing review of the material will demonstrate that sources of stress are varied and quite probably unlimited.  Now let’s briefly look at the behavioural mechanics of stress and how it narrows mental functions.  As we heap stress loads on our diver he becomes less sensitive to his environment and less able to intelligently focus on problems.  These interferences with mental thought processes manifest in several classic ways:

  • Perceptual narrowing wherein the diver is unable to notice or deal with subtle developing aspects of a situation and perceives only the broadest or more obvious elements of a problem.  At depth, the effects of such narrowing are more serious.  A diver who finds himself unable to maintain neutral buoyancy and continues to fixate on depressing the inflate button of his BCD to no avail has lost the intellectual ability to perceive another solution to his problem.
  • Cognitive or analytical narrowing wherein the diver is hampered in his ability to analyze a problem.  Example: a diver barely reaches his decompression stage bottle because he was low on air.  As he begins his 20-foot (6.1m) stop, he has trouble breathing but the indicated pressure is 2500 psi.  Under sufficient stress he may not realize that the valve is not open all the way or that switching to the ‘octopus’ would solve the problem.
  • Response narrowing occurs when the diver is unable to focus skills and knowledge on problems.  This typically manifests with loss of poorly learned skills or behaviour.  Overlearned, reflex action type skills are retained longest.  The obvious importance of drills and skill repetition until reactions to certain situations are second nature cannot be over emphasized.
  • Panic is usually described as unreasoning fear, the ultimate plateau of mental narrowing.  Smith (1979), “As stress increases, the diver’s ability to diagnose and respond to them properly may diminish accordingly.  In any stressful situation, it is critical for the individual to break out of this escalating cycle as quickly as possible and early detection is important.  Thus, it is desirable to recognize the early symptoms of stress in your own behaviour and in the behaviour of others before these symptoms reach panic proportions.  Panic is the end of the line.  It is usually terminal and contagious.

The anticipation of problem situations during a dive and the ability to adopt contingency plans calmly and rationally are vital in all levels and types of diving.  Experience plays a great role in the individual’s ability to deal with stress and to formulate alternative reactions to threat scenarios.  Overlearning of all relevant skills and complete familiarization with equipment is necessary.  If overlearning can be taken to its highest level, then much of the reactive behaviour in an emergency will be reflexive and not require conscious thought processes.  Smith (1979) notes, “Overlearning takes all doubt out of human performance under stress as far as that particular skill is concerned.  This not only greatly reduces the probability of human error on certain tasks but also frees the diver’s mind to deal confidently with more complex aspects of the problem.”

Stress accompanies us everywhere and is magnified in deep diving activities.  Know yourself; know your buddy and/or your diving team.  Dive within your limits.

Signs of Stress

  • Rapid breathing, hyperventilation
  • ‘Wild-eyed’ look
  • White-knuckle gripping; muscle tension
  • Rapid, jerky, disjointed movements
  • Irritability, unreasonableness
  • Fixation, repetitive behaviour
  • High treading, attempts to leave the water
  • ‘Escape to the surface’ behaviour
  • Stalling
  • Imaginary gear problems or ear problems
  • Contact maintenance (e.g. clutching swim ladder, anchor line)
1 Comment Leave A Reply

One Response to “Under Stress”

  1. JOSE

    Dear friend: you dont suffered any sympthoms narcotic,toxicuty oxygen at 138 meters…… which was the bretahing techniques you did..
    you were alone….? a huge embrace from latin america

    In 1990, I deliberately chose a single cylinder (115 cu. ft.) and regulator package to lessen my equipment load on my record 452-foot (138m) compressed air dive. With proper breathing techniques, etc., I was able to comfortably complete the dive on this reduced rig.


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