Recent studies are beginning to suggest that episodes of panic or near-panic may explain many recreational diving accidents and possibly throw light on the cause of some diving fatalities.

Most think of scuba diving as taking place in a serene paradise surrounded by beauty and the thrill of weightlessness, but in a recent national survey, more than half of divers reported experiencing at least one panic or near-panic episode, according to William Morgan, director of Sport Psychology Laboratory at the University of Wisconsin-Madison and the principal author of the study.

The panic attack was often spurred by something that a non-diver would deem serious — entanglement, an equipment malfunction or the sight of a shark. But the attacks don’t make things better, instead, they can lead to irrational and dangerous behavior. If divers and instructors knew more about the phenomenon, Morgan adds, they could screen out people who might be susceptible to life-threatening panic attacks.

The primary cause of diving fatalities is listed as drowning, 60% of all deaths usually caused by specific problems such as lack of air, entanglement (in fishing nets, rope or kelp), air embolism, narcosis and panic.

In Morgan’s study, over half of the scuba divers reported that they had experienced panic or near-panic episodes on one or more occasions. Panic was significantly higher in women (64%) than in men (50%), but more men(48%) perceived the events as being life-threatening than women (35%).

The panic attacks are not restricted to beginning divers; sometimes experienced scuba divers with hundreds of logged dives experience panic for no apparent reason.It is thought that in such cases the panic occurs because divers lose sight of familiar objects, become disoriented and experience a form of sensory deprivation. This problem has been labeled the “blue orb syndrome.” However, among inexperienced divers, there is usually an objective basis (e.g., loss of air or a shark) behind the panic response.

Panic response is when a diver behaves irrationally. There is usually an observable stimulus responsible for this behavior, such as the sudden appearance of a shark, loss of visibility, loss of air, entrapment in fishing line, or any unexpected occurrence perceived by the diver as a threat. The diver’s attention narrows and he loses the ability to sort out his options. If, for example, a problem develops with the air regulator, the restricted air flow could prompt the diver to ascend rapidly enough to cause an air embolism (bubble) in the bloodstream, which can be fatal. This would be considered a panic response if the diver had other safe options, such as access to a pony bottle (an emergency air supply), or was diving with other divers who could share their air supply, allowing a gradual ascent.

There are some obvious diving activities which tend to lead to panic episodes, such as the stresses of equipment malfunctioning, dangerous marine life (e.g., sharks), loss of orientation during a cave, ice or wreck dive, and so on. Diving with faulty or inappropriate equipment or performing high-risk dives has greater potential for panic episodes; these problems can be prevented or minimized with appropriate training and cautionary actions.

There is a psychological concept known as “trait anxiety” that is regarded as a stable or enduring feature of personality, whereas state anxiety is situational or transitory. In this regard, it can be accurately predicted that individuals who score high on trait anxiety are more likely to have increased state anxiety and panic during scuba activities and are at potentially greater risk than those scoring in the normal range. However, David Colvard of Raleigh NC has found that trait anxiety only predicts panic or near panic in student divers, not in certified divers. He feels that this may be self-selecting after initial training.

Some feel that these people probably should not dive because it has been found that interventions such as biofeedback, hypnosis, imagery and relaxation have not been effective in reducing the anxiety responses associated with the panic attacks.

Psychological research has shown that hypnosis is effective in relaxing scuba divers, but it can also have the undesired effect of increasing heat loss in divers. Relaxation can lead to increased anxiety and panic attacks in some “high anxious” individuals (this phenomenon is known as relaxation-induced-anxiety, or RIA). Individuals with a history of high anxiety and panic episodes should probably be identified and counseled during scuba training classes about the potential risks.

The risks and dangers of scuba diving are not well known among recreational scuba divers. Since 1970, the number of annual U.S. scuba diving fatalities has varied from a low of 66 to a high of 147. The real severity of the problem is masked by several unknown variables, having to do with the total number of divers.

First, the total number of active scuba divers is unknown. Estimates range from 1.5 to 3.5 million in the United States alone and therefore, valid estimates of risk using traditional methods are not possible. Fatality estimates range from a low of 2-3 per 100,000 to 6-9 per 100,000, depending on the number of fatalities and estimations of the number of active divers in a given year.

Second, most studies of diver fatalities define a diver as someone certified as a diver. This is problematic because some individuals (a) scuba dive, but have not been certified, (b) are certified and never dive, and (c) may hold as many as 25 advanced level certifications with the result that such a diver would be treated statistically as 25 divers.

Third, risk estimates in this activity have not considered the fact that someone who dives once in a given year is treated statistically in the same way as a diver who makes several hundred dives.

The risk of scuba diving causing non-fatal accidents is also difficult to answer because we don’t have valid data on the number of active divers or an estimate of degree of involvement or exposure. We do know that approximately 600-900 divers are treated for decompression illness (DCI) in the United States each year. This category includes decompression sickness (DCS) and arterial gas embolism (AGE).

Nine hundred and fifty-eight cases of DCI were treated in the U.S. during 1993. However, this figure includes neither divers who experienced DCI but did not seek treatment, nor does it include those who sought treatment but may have been treated for other problems.

Furthermore, a wide variety of additional problems such as cardiopulmonary difficulties, near-drowning episodes and musculoskeletal injuries occur each year. It is unknown what proportion of these problems go unreported.

Anxiety and panic are not discussed in commonly used instructional materials of the national certifying bodies involved in scuba training. Panic, along with the problems that can occur in scuba diving as a consequence of panic, isn’t even addressed in these training manuals.

Here are some excellent presentations about panic by a diving psychiatrist, David Colvard, MD. These are Powerpoint Presentations that may be downloaded, authors permission.