Stress in Diving

I don’t want to participate in any sport in which my
species is not at the top of the food chain.
Ken Fonte

Stress in diving is probably the central problem in
the accidents and resulting injuries and fatalitiesthat occur to divers . . .
Art Bachrach and Glen Egstrom

STRESS

Many divers do not seem to place traditional activities in the context of stress-inducing scenarios.  Diving is supposed to be fun, right?  The following passage is excerpted from Bachrach and Egstrom’s (1987) Stress and Performance in Diving:

“We will cover your nose and eyes with a rubber and glass cup that will give you tunnel vision and prevent breathing through your nose.  A snorkel which is partially filled with water will increase breathing resistance, especially when you work harder.  A rubber suit will increase your surface area and your buoyancy while creating a restriction over each of the body’s joints.  (A partial adjustment will be made by fastening 15-20 pounds (6.8-9.1 kg) of lead to your waist.)  Fins for your feet will make walking more difficult and require more energy when swimming.  A buoyancy compensation device will provide additional drag, especially when it is inflated to increase your buoyancy.  Approximately 40-50 pounds (18.2-22.7 kg) of steel or aluminum will be fixed between your shoulder blades by means of a backpack with a series of straps and buckles, which will terminate somewhere under the buoyancy compensator near the weight belt buckle.  A regulator with various and sundry hoses and gauges will be attached to the tank and will cause you to breathe against an added resistance both during inhalation and exhalation.  Various other items, such as knives, gauges, goody bags, cameras, spear guns, gloves, hoods and booties will be added for your comfort and convenience.”

These learned authors (by this humorous accounting) have accurately placed into perspective the realities of the stressful environment that scuba divers willingly subject themselves to.  By necessity our sport is “equipment intensive” and simply donning that equipment can produce levels of stress far in excess of what the average person may be comfortable with.  Indeed, divers have been observed to reach heart rates approaching 200 beats per minute… nearly 3.5 times the normal rate, just gearing up!

Technical diving not only subjects the participants to added stress but the deeper environment also makes coping with such performance detriments critical.  In our discussions we are most concerned with recognizing the early effects of stress and dealing with the effective management of these stimuli underwater.

Stress is variously defined: McGrath (1970) describes it as “a result of an imbalance between the demands placed upon an individual and the capacity of the individual to respond to the demands.”  Sells (1970) states, “For a situation to be stressful the individual must perceive the consequences of his failure to be important.”  These two views provide perspectives from both the physical and mental effects and clearly show the potential for compound stress stimuli to be at work simultaneously in the diver.  Smith (1979) provides a succinct overview, “in the context of human behavior, stress might be regarded as a force that tends to break down an individual’s ability to perform.  Physical stress tends to weaken or injure the diver; psychological stress leads to behavior impairment.”

The role of stress in technical diving applications cannot be ignored.  Typical reactions to stress include such signs as rapid breathing or hyperventilation, the consequence of which should be immediately apparent.  Importantly, stress is so varied to individuals that even what may be considered a “routine” problem can be highly stressful in some divers.  Bachrach and Egstrom (1987) describe stress as “basically learned” and this perception is learned through “modeling” behavior.  If your mother was afraid of reptiles, this phobia may well be passed along to you subconsciously.  Likewise, many of the public has an inherent dread or horror of sharks or moray eels with no actual experience to justify such fear.  Experienced resort guides think nothing of hand-feeding eels or swimming with sharks but to the uninitiated the mere appearance of such a creature can rapidly induce stress reactions that can lead to near panic.

We all probably have a few skeletons rattling around in our mental closets… some that we may not have even a vague recognition of.  Well-experienced divers have reported extreme anxiety in their first encounter with “silting-out” situations in caves or wrecks.  Willful control of this stress anxiety through discipline and fallback on training can prevent escalation to a threat scenario.

SOURCES OF STRESS

“Time pressure” is a classic method used by psychologists to alter experimental testing and induce error by test subjects.  Problems that are easily accomplished become increasingly difficult and sometimes impossible if the element of time is introduced as an opponent.  Diving, especially deep diving, is time dependent: we only have so much allotment due to constraints of decompression and/or gas supply.

This emphasizes the importance of dive planning so that orderly progression of the dive is maintained within the dive envelope calculated.  Deviations from the plan can cause rapid acceleration of time pressure stress inducements.  This is true not only for the dive itself but for pre-dive activities such as gearing up.  Do not allow yourself to be hurried into mistakes.  How many times have you observed divers entering the water without a mask or without fins?  Simply putting the gear on an empty cylinder without checking its pressure happens too often.

“Task loading” is another factor well known to produce errors in performance.  Simple enough: give the diver more projects (tasks) to do than he reasonably can accomplish in the time period allotted.  Or give him competitive, multiple jobs that require him to do two or more things at the same time.  Divers are already burdened with monitoring gauges, keeping track of their position underwater (pure navigation and also depth trim), noting the performance of a buddy, etc.  Add to this equation an underwater camera system or duties requiring written observations and we have a fairly well “task loaded” diver before any contingencies may arise.  And let’s remember that all this activity is being attempted in water deep enough to have effects from narcosis and gas density for breathing purposes.

Environmental considerations such as current, cold water or reduced visibility will all contribute to stress loading.  Further, physical exertion to deal with such environmental detriments and any normal exertion on the dive will lead to compounding of stress factors.

Equipment alone can be a primary source of stress inducement simply due to its bulk, weight, drag etc.  Take note of the experienced diver whose gear is streamlined and well organized.  This individual will be wearing a BCD selected for its suitability for the dive situation.  Tropical wall diving in warm water is far more easily accomplished with a light wet suit (2mm) or dive skin with a neoprene vest.  Combining this with the newer editions of BCD’s that feature less volume, form fitting styles and a full-foot power fin eliminates the needless bulk of heavier wet suits, booties etc.  Gauges conveniently mounted in a single console with a dive computer provide easy viewing and no distractions of arm or wrist attached devices.  Combining the “octopus” second stage into one of the inflator/second stages further streamlines the diver.  A light-weight belt sized for neutral buoyancy at low tank pressures (to facilitate safety and/or decom stops) completes the package.

Obviously, this equipment package must be modified as we deal with cold water, cave or wreck situations but the emphasis on effective management of equipment should be obvious.  Consider the equipment stress of the diver outfitted for deep water mixed gas wreck diving: we see him in a dry suit, dual 120 cu. ft. cylinders, redundant regulators and gauges, redundant BCD’s and inflators, heavy weight belt, lift bags, decompression reels, and, in many cases, stage bottles of Nitrox and oxygen clipped to his rig.  This individual may well have in excess of 200 pounds (91 kg) of equipment strapped to him.

All this adds up to a diver who is heavily predisposed to performance- limiting detriments before he ever leaves the surface.  Indeed, this individual may already have exceeded his physical limits to safely conduct a dive simply due to the equipment load he has strapped on.  Is this a comfortable, relaxed diver?  Maybe…  but add a rough sea and a pitching boat with a violently surging swim platform or ladder, and unless this diver is a superior physical specimen, it will be a major stress loading activity to deal with the equipment and get into the water safely.

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 cu. ft. 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 lesson my equipment load on my record 452 fsw (137 m) 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 do 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 our 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 was focused on a specific goal and was of limited duration. In such extreme depths on air, I balanced my gas volume needs based upon vast experience against my 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 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 need.

Divers should be aware in intimate detail of their personal gas consumption rates at a range of depths and 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 up to 200 fsw, a single BCD is probably adequate with an oversized single cylinder and a regulator with DIN fittings. Some would like the redundancy of a Y-valve for regulator back-up. Fine…we are still dealing with a manageable gear package. The same dive conducted on northeast wreck will 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 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 do dives within their own 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 any supposed negative peer reactions, 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 with which they are uncomfortable.  The emotionally mature diver can abstain from diving in any situation with no attendant ego damage.  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 we shall briefly look at the behavioral mechanics of stress and the resulting mental narrowing.  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” whereby the diver is unable to notice or deal with subtle developing aspects of a situation and perceives only the grossest 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” whereby 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 upon problems.  This typically manifests with loss of poorly learned skills or behavior.  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 overemphasized.

“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 behavior and in the behavior of others before these symptoms reach panic proportions.  Panic is the end of the line.  It is usually terminal and contagious.”

SIGNS OF STRESS

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

SUMMARY

The anticipation of problem situations in 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 presented.  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 behavior 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.