Why Divers Die

It’s my general observation that as a class, divers aren’t in good physical shape. While many people consider diving a sport, to engage regularly in most sports (unless it’s bocci or horseshoes), one needs to be in reasonable shape.

Diving is recreation, and like many forms of recreation a participant with flimsy muscles, a sizable spare tire, and no aerobic conditioning can enjoy it. In fact, in a recent study of DAN members (1674 responses out of 3000 questionnaires), 43.1 % had body mass calculated as ideal, 40.0% as overweight, and 13.6% as obese. So for divers who aren’t in decent shape, all they need to do is find a dive operation — and there are scores — that will let them sit on the transom while a deckhand brings a tank and then simply slip into the calm water.

But easy diving can create a false sense of security. Having to make a long surface swim, fight a current, or scramble back on a boat with no ladder are tests that can overwhelm an out-of-shape diver. While strength is helpful in diving, stamina is crucial. And stamina can only come with good aerobic conditioning.

To be a safe diver, one needs good lungs and a strong heart. While genetic factors can produce heart disease, fatty diets, lack of exercise, smoking, hypertension, and the like are serious causes. Get into a stressful situation, and the extra effort required of a weakened heart or clogged arteries may be fateful. It’s not surprising that lack of conditioning shows up as a serious factor in many diving deaths. And cases from DAN and down under demonstrate that.

In this case, a 49-year old male, a smoker, returned to diving after an 18-year hiatus. On his third dive after that long break, in an advance certification class, he made a shallow dive, then began a simple 25-yard surface swim back to the boat. He disappeared, only to be found unconscious on the bottom. The autopsy revealed significant cardiovascular and pulmonary disease in this severely overweight diver. That’s what did him in.

A 67-year-old instructor had several hundred dives. Five minutes into this one, his regulator dropped from his mouth. Others divers rendered aid, including CPR, but he was pronounced dead at the local recompression chamber. His physician had recommended a treadmill test to check his heart function, but he declined. He died of an acute myocardial infarction due to coronary atherosclerosis.

Drugs, both legal and illegal, can rain terror on the heart and, under the stress of diving, lead to death. Take, for example, this 49- year-old male who dived infrequently. He felt uneasy after entering the water, so he decided to abort the dive and get back into the boat, only to collapse while climbing up the ladder. The autopsy revealed cocaine in his system, which commonly causes cardiac dysrhythmias.

Even nonprescription drugs can produce symptoms and results similar to cocaine. This 49-year-old male, whose death was preceded by cardiac dysrhythmia, had difficulty equalizing his ears during the descent to 40 fsw. He returned to the surface, but had difficulty swimming back to the boat. After disappearing below the surface, he was pulled from the water but could not be resuscitated. While the autopsy revealed evidence of cardiac disease, the toxicology report contained the most significant finding: he had more than ten times the therapeutic level of chlorpheniramine and more than twenty times the therapeutic level of phenylpropanolamine in his blood. Chlorpheniramine, an antihistamine, is found in many over-the-counter allergy and cold remedies. It sedates and impairs, and even in small doses can be the equivalent of a .08% blood alcohol reading. Phenylpropanolamine is found in over-the-counter diet pills; it can increase blood pressure and, like cocaine, it can inflame heart muscles. These two drugs, taken in excessive doses together, were considered the cause of the diver’s death.

Heavy breathers who use their air quickly need to consider whether it reflects anxiety or if they're simply out-of-shape. In this case, a 57-year-old male made an annual dive trip for the past 10 years (though he seldom dived between trips). He often used his air before the other divers and typically ascended several minutes before his buddies. After a 20- minute dive to 55 fsw, he signaled to others that he was going up. He went to 15 fsw, stopped, and was next seen floating on the surface without his regulator in his mouth. Resuscitation procedures were unsuccessful. While he drowned, the autopsy found heart problems; a cardiac event was the likely cause of the death.

Too often, divers die because they forget or fail to drop their weights. In this case, a 21-year-old male who had made six lifetime dives joined a more experienced diver for a night dive to 95 fsw in cold water. He had forgotten his fins. The experienced diver lent him one of his, so both wore only one fin. When both became low on air, they decided to surface, but the less experienced diver had difficulty getting off the bottom. His buddy tried to help, but the decedent was combative, and the buddy had to surface rapidly without a regulator in his mouth, which resulted in the bends. His inexperienced buddy died: he was overweighted, didn’t have the fin power to kick up, and didn’t think to increase his buoyancy by inflating his BC.

This 39-year-old open-water certified male had seven lifetime dives. With his sister and brother-inlaw, he descended to 60 fsw for 20 minutes but became separated from the other two divers. When his body was recovered off the California coast, he still wore his 55-pound weight belt; his tank was empty.

Four family members had completed their certification a week before their live-aboard trip on the Great Barrier Reef. After two daytime dives, the victim, her husband, and twelve others joined three instructors for her first night dive. Divers were to choose their own buddy pairs, which permitted experienced divers to pair with one another, inevitably leaving inexperienced divers to buddy up. (While this practice keeps experienced paying customers happy, it’s not necessarily safe.) While the victim and her husband had been told they could have an instructor accompany them, the divemaster selected an experienced diver as his buddy. Apparently, he thought his job was only to be a guide, and he was unaware of any responsibility for the safety of the pair. The couple descended after the divemaster and his buddy. When they reached the bottom, they found the divemaster and his buddy had not waited for them. Thinking they had seen a light disappear behind some coral, they set off to join their guide, but failed to make contact. The victim appeared disoriented and made her way back to the surface, but she wanted to resume the dive, which they did. While she had no problem descending, her buddy later reported that she had “a buoyancy problem” and was overweighted. They descended to 18m, though the dive plan was to go no deeper than 10-12 meters. The divemaster later said he saw them below him but was unable to dive to them because he couldn’t equalize his ears. His attempts to attract their attention by shining his light failed; he never thought to send his buddy to them and did not regard them as being in danger. Soon the victim made a rapid ascent. Her husband noticed she had trouble breathing and her eyes were glazed as he ascended with her. However, “she suddenly dropped away and dropped like a rock to the sea bottom.” He was unable to prevent her descent to the bottom, where he found the regulator was out of her mouth. She grabbed his regulator, but he was able to get her to use her own; then it came out again, and he was unable to replace it.

He was running low on air and had to ascend. He didn’t think about trying to ditch her weight belt or inflating her buoyancy vest. When he reached the surface, others went to find her, which was easy as she had a cyalume light stick attached to her tank. When her buoyancy vest was inflated she began to lift off the bottom; on the surface resuscitation failed.

In most deaths several factors contribute, as they did in this Australian case: a lack of conditioning, unfamiliar equipment, failure to drop a weight belt, etc. The victim had been certified just two weeks before. Making a night dive with 5 others, only one of whom was experienced, he surfaced after 26 minutes in 30 feet of water. For a second dive, he took another tank, using the BCD mounted on it, which was different from his own, and proceeded with two other divers. After several minutes, they decided to surface from 25 feet; at 13 feet the victim indicated he was out of air and swam vigorously toward the surface. One of his buddies tried to help him by holding his equipment and pulling him. But he pulled his mask off and let the regulator fall from his mouth during his ascent. At the surface he gasped a few short breaths and said he was out of air. He failed to use the octopus offered by his buddy and thrashed about trying to float. He pressed the deflate button on the buoyancy vest, presumably intending to inflate the vest, though he had no air remaining. Then he sank but was quickly retrieved. He took a breath, then sank again. He was unconscious when found on the bottom; his buddy ditched his weight belt and inflated her vest to bring him up. He never regained consciousness.

The BC was tested by being orally inflated underwater. It failed to bring the backpack up, so was an unsuitable piece of equipment. However, there is no evidence that he ever inflated it. His drowning resulted from his panic at being over-weighted and out of air at the surface, a situation aggravated by wearing a borrowed tank (heavier than his usual one) and BC with a different inflation/deflation button placement than his own. He was overweight but not obese. His father regarded him as too unfit to scuba dive, so he took care not to let his father know of his dive plans. An autopsy found up to 50% atherosclerotic narrowing of some of his coronary vessels.

Sadly, each year we note that foolishness is too often the cause of death. In this first case, a 14-yearold boy who received his junior certification a couple of months before this dive joined his father to spear fish. It was the sort of dive that a no father should organize for his son. Both began the dive with less than half a tank of air and descended to more than 80 feet. After deciding to ascend, they briefly became separated. The boy was next seen descending below 100 feet without his regulator in his mouth. The father pulled his son up from 285 feet, but resuscitation was unsuccessful.

And while this next case qualifies as foolishness, it was driven either by bravado or despair. This 25-year-old dive instructor was distraught over a breakup with his girlfriend. He told people he would go to 350 fsw on one tank and bring a computer along to prove the profile. His body was never recovered.

In another unusual case, this time from Australia, a fellow who was not a good swimmer decided to borrow a mask and snorkel from his traveling buddies and give it a go. He was cautioned to avoid venturing into water where he was out of his depth, so he went in where the water was only up to the top of his chest. After a while his friends left the water, but they sat on nearby rocks and watched him, though not continuously. Five minutes later they could no longer see him. They walked along the beach to look for him, became worried, and sought help. His body was found 42 hours later, floating in the area where he had last been seen. Apparently, he panicked and drowned, not thinking to remove his mask and stand up.

Enough cases for this year. We offer them so that you can learn to save yourself, either in the water or even before the dive, by not making dives you shouldn’t. Hopefully, this series will help you recognize the error potential of other divers, so you may steer them from a fatal mishap. Either way, we trust these articles will ensure that neither you nor your buddies will become illustrations in the next series of Why Divers Die .

— Ben Davison