In cases where the Edmonds summary found cardiac failure was implicated there was either gross cardiac pathology or a clinical indication of cardiac disease in the autopsy findings. The associated triggers include exercise, drugs, hypoxia from salt water aspiration, cardio-pulmonary reflexes, respiratory abnormalities, restrictive dive suits and harness, and cold exposure. In other surveys this correlation is not so clear.
Surveys have shown that between 0. Edmonds considers that the statistics imply that asthma is a significant risk factor and that asthmatics should not be permitted to dive. This opinion was prevalent for a long time, but recent studies by DAN suggest that asthma may be managed successfully in some cases. Factors contributing to death in this group include panic, fatigue and salt water aspiration, and the cause of death was usually drowning or pulmonary barotrauma.
The diving environment can provoke or aggravate asthma in several ways, such as salt water aspiration, breathing cold dry air, strenuous exertion, hyperventilation. It was often caused by sea sickness or salt water aspiration or ingestion, but ear problems and alcohol were also cited as causes. Equipment Edmonds et al. This is not necessarily contradictory, as they include incompetent operation under equipment failure and specify overlap between malfunction and misuse.
Subsequent testing of the regulators showed that most of the problems were caused by leaks resulting in inhalation of salt water, but in some cases there was excessive breathing resistance following a mechanical dysfunction. In a few cases the regulator failed catastrophically, or the hose burst.
The difficulty of breathing from the regulator was often aggravated by other factors such as panic, exhaustion or badly adjusted buoyancy. This was usually due to a problem with the inflator mechanism, but in some cases the BCD could not stay inflated. Overweighting can also be classified as misuse of equipment. Edmonds et al. This was sometimes due to defective or ill fitting fins, but in most cases the cause was not apparent. Environment Edmonds et al.
In many cases they divers surfaced because they ran out of breathing air. These included current stronger than the diver could manage, rough water, surf, surge from wave movement, and impaired visibility caused by these conditions. The fatal dive was often the deepest ever for the victim.
Greater depth can expose a diver to factors such as increased air consumption, impaired judgment caused by nitrogen narcosis, colder water, reduced thermal insulation of a compressed wetsuit, reduced visibility and lighting, slower response of buoyancy compensator inflation, increased work of breathing, greater heat loss when using helium mixtures, higher risk of decompression sickness and a necessarily prolonged ascent time.
Other environmental factors cited as contributory to fatalities include caves, marine animal injury including shark and other animal bites, and marine stings, difficulties entering and exiting the water, cold, entanglements, entrapment, and night diving. Experience The DAN fatalities workshop of found that there is a real problem that divers do not follow the procedures they have been trained in, and dive significantly beyond their training experience and fitness levels, and that this the basic cause of most accidents.
This is consistent with several scientific studies. Medical issues are a significant part of the problem, and certified divers are responsible for assessing their own fitness and ability to do any particular dive.
Accident investigation Diving fatality investigations are intended to find the cause of death by identifying causative factors. Three main areas of investigation are common:. Equipment is investigated to look for issues that may have contributed to a cause of death.
Procedural investigation considers whether the diver followed appropriate procedures, adequately prepared themselves and their equipment before diving, or went diving in conditions beyond their training and experience level.
Lack of solid information about the underlying causes of diving accidents and fatalities creates uncertainty, and this is the principal factor leading to litigation, higher insurance premiums, massive litigation costs and ultimately the continued loss of life.
There is usually some form of investigation following a diving fatality. There may be several investigators representing different parties. Police are likely to look for evidence of homicide, The maritime safety authority will investigate in cases where a death occurs while diving from a vessel.
In most cases, the investigation takes place some time after the event. Whether permanent or temporary, any health condition that impedes your ability to be alert, to recognize and respond to environmental conditions, and otherwise safely plan and complete a dive should contraindicate diving.
Even after you recover from your illness or your chronic condition is back in check, your body needs time to recover from the effects of your medical complication. For example: Your cough may be gone, but it may take time for your chest congestion to clear. Rushing into the water before you're physically able to breathe deeply can leave you starved for air, which may lead to panic.
In this situation, trying to breathe deeply when the body just is not able to causes you to feel as though you cannot get any air at all. This leads to stress, which can lead to poor decision-making or worse, full-scale panic. Procedural errors common to dive accidents include buoyancy control problems, rapid ascents, missed decompression stops, general skill limitations, ear equalization problems, and, most critically, failing to properly monitor the air supply, resulting in low-on-air or out-of-air situations.
In some cases, the diver lacked the appropriate training for specialized activities like diving in the overhead environment of caves or wrecks or deep diving. In other cases, the diver stayed within the scope of his training, but his emergency response skills simply weren't up to the challenge.
Open-water environments can change rapidly, and divers who are unprepared, out of practice or physically incapable of adapting to those changes can become victims. Weather and water conditions obviously have a crucial effect on whether or not it's safe to dive. So why can't dive staff crack down on divers, especially novice divers, when conditions look less than sublime? A year-old diver with only 14 dives in his logbook rented dive gear while abroad and went with a group to an area known for strong currents.
He used his air quickly, so the dive guide ascended with him, but later reported they had difficulty resisting a downcurrent. At nine feet deep, the guide signaled to him to grasp some kelp, but the victim let go and was last seen carried away by a strong undertow.
The risk of injury or death shoots up when a diver gets separated from the group. This is what happened to a year-old diver who somehow got separated from a guided group of divers and surfaced alone in rough sea conditions. He was seen struggling to get to a tag line but sank before anyone on the boat could reach him.
That's why it's wise to stick like glue to your buddy or guide in less-thanideal conditions in the water. Every report has cases of divers who went out with unfamiliar or improperly rigged equipment. A tragic example of this was provided by a year-old male diver who, even though he had a number of different diving certifications, had not dived for a long time, but wanted to try out a new drysuit and new computer. Ascending with his buddy from a foot bounce dive, with a brief stop at 65 feet, he started struggling with his equipment.
At 20 feet, he was struggling with his mask. His buddy assumed he was out of air and gave him his own alternate, but the victim lost consciousness before they reached the surface and later died. It turned out his main regulator, long overdue for maintenance, was hard to breathe from at depth. His primary tank was empty, and his secondary supply, a pony tank, was mounted in such a way that its regulator's second stage would not reach the diver's mouth.
BSAC noted a significant number of incidents involving the use of surface marker buoys deployed from depth. That's because decompression-stop diving is more common in the U. But in these incidents, the diver often got entangled in the line and got dragged upward in an unscheduled and often rapid ascent. Contaminated air is another thing to watch for -- faulty compressors in dive shops or on liveaboards are unfortunately not that rare. Look at the compressor's air intake to ensure it's not near any source of carbon monoxide, like the boat engine's exhaust.
A rudimentary inspection of the tank you're supplied can alert you to possible problems and any dive operation should have a portable analyzer available , but you usually have to trust that the tanks supplied are in good shape. A British diver on a dive resort vacation last September found that his recently serviced regulator became gradually more difficult to breathe from.
All of the five root causes of the triggering event can result in arterial gas embolism. Poor buoyancy control can also result in drowning, without AGE, and other problems.
In fact, buoyancy control is the hardest diving skill to learn, and the easiest to forget. Diving occasionally over the last couple of years it always takes me two or three dives to reacquire the excellent buoyancy control I used to have as a cave, drysuit, rebreather diver.
Buoyancy control problems nearly killed me once and were a major factor in the diving death of a good friend. Over divers have died in caves and therefore the following recommendation should be no surprise. This becomes even more important if you have logged only a few dives or if it has been a long time since you last dived on a regular basis.
The bottom line is that dive fatalities are relatively uncommon, and the vast majority of them could have been avoided with a few simple precautions. I have been involved in quite a few diving fatality investigations. In most accidents almost always it is the victim who is at fault. Keep fit, keep healthy, and dive within your limits to reduce your risk of dying while diving to an absolute minimum. I do not think you are comparing apples to apples here.
If you have those statistics the comparison would make sense. Click here to cancel reply. By Dr. Divers Alert Network is seeking talented undergraduate and graduate students to assist with its dive safety and medical research this summer. Words by Lorie Laroche and Dr. Neal W Pollock Health is a state of overall physical, mental, and social wellness.
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