Why Divers Die

Every year, hundreds of divers die around the world. Their deaths are usually caused by bad decisions they make, like diving beyond one’s level of competence, diving with known medical conditions or diving in bad sea conditions. Most dive-related deaths are avoidable, and many of the incidents might have had better outcomes through better training, better knowledge of the associated risks, appropriate medical screening, better gear maintenance -- and just plain common sense.

Since our founding in 1975, we have published significant dive fatality cases so that our readers might better prepare themselves for safe diving. Divers Alert Network’s Asia-Pacific division publishes the most detailed cases of diving and snorkeling fatalities; its latest report covers dive deaths in Australian waters in 2010. We hope that by explaining these cases, divers will understand better how they could contribute to their own demise, and exercise proper judgment throughout their diving career.

Tropical Divers to Cold-Water Divers

A preponderance of our readers make all their dives from resorts and liveaboards in tropical waters, and smart ones know that tropical training and experience can’t be transferred to cold water beach diving. This 31-year-old woman had been certified in the warm waters of Thailand and was making her first dive in nine months in much colder water in Australia. That meant a 5mm semi-drysuit, with which she wore 20 pounds of weight, far more than she was used to. She and her buddy made a shore dive, with visibility much lower than in tropical waters, and after 20 minutes in shallow water, her buddy couldn’t see her. Rather than continue searching, he went to the local dive shop for help. Divers soon found her lying on the bottom, face up, at 13 feet, regulator out of her mouth. She was dragged into the boat, unconscious, and CPR couldn’t bring her back. While the buddy system breakdown was tragic, heavy weights, new gear and cold water were serious contributors.

The Perils of Diving -- or Even Practicing -- Alone

A fit 27-year-old freediver was practicing breath-hold in the five-foot-deep pool of his apartment complex. At some point, another apartment tenant walked by and noticed him lying at the bottom, unconscious. Ten minutes later an ambulance arrived and hauled the man out, noting that he had regurgitated. At the hospital, a CT scan showed severe hypoxic brain injuries, and he died the next day. Even though she hadn’t dived in 11 years, this 46-year-old woman woke up one morning and, for some reason, decided to bike to the beach, towing her gear in a wagon, for a shore dive. The choppy waters were only 64 degrees, and visibility was less than six feet. Six hours later, her bicycle was still in the same place, and she was reported missing. Police divers found her body two days later, in three feet of water, 500 feet from where she had started, her tank empty. Tests found her regulator to be in poor condition, with sediment deposits, corrosion, and distorted O-rings, among other things. The BC inflator was faulty, leaking air into the BC, indicating that she would have needed to dump air regularly to keep her position in the water. She was also wearing a too-thin wetsuit for that water temperature, and too much weight. Speculation is that she ran out of the air and drowned, but with all these issues, anything might have happened.

Bad Conditions? Scrap the Dive

When the conditions are bad, resort boats don’t go out, and liveaboards may not let their divers in the water. Divers off on their own, however, must make their own decisions, but because they have driven long distances to dive, or perhaps have a buddy intent on diving, some, against their better judgment, proceed with dives they should have scrapped.

This 46-year-old diver was already anxious when setting out with her buddy on a shore dive in a sheltered harbor. As they finned toward a rock wall, she indicated her dive computer wasn’t working, but they carried on. At the wall, the buddy checked her tank and only saw 1400 psi, but they decided to keep on diving past the wall. Forty minutes later, the woman grabbed her buddy’s arm and showed her gauge: 300 psi. The buddy gave her his octopus, but five minutes later, at 23 feet, the woman grabbed her buddy’s arm and indicated she wanted to surface. On the surface, she gasped for air and couldn’t speak, only communicating by nodding or shaking her head. The divers were 300 feet from shore and swamped by waves, so her buddy said they should re-descend, but the woman couldn’t use her regulator or snorkel, even with her buddy’s help. He rolled her onto her back and started to tow her while she kept gasping for air, then went unconscious, with froth pouring from her mouth. A nearby boat got her to shore in eight minutes, but waiting paramedics couldn’t shock her heartbeat back. Police later found that there was a big leak in the hose attached to the BC, which explained her high air usage, but her not paying attention to her anxiety and lack of air at the beginning of the dive set the stage for its fatal end.

What is Buddy Responsibility?

Of course, every diver is responsible for himself, but what should a diver do when it’s clear to him that his buddy is not operating on all cylinders? Do you let it pass, ask a few gentle questions (“Are you ok?”), get tough (“Jack, you really shouldn’t be diving today”), or just refuse to go so your buddy won’t.

In this case, the buddy was observant but passive and went along for the ride with his experienced, 51-year-old cave-diver friend. He noted his friend had been unhappy, withdrawn and distracted all weekend, and needed several reminders about usually routine aspects of dive preparation. Outfitted with a new drysuit and regulator he was trying out, he ascended into a cave. He looked clumsy, his buddy noticed, and needed help dropping his travel air tank after the eight-minute descent to 115 feet. He didn’t respond to his buddy’s signals and may have been suffering nitrogen narcosis. Regardless, his buddy dropped to 170 feet before noting his friend was above him at 150 feet, inverted in his drysuit. The buddy rose and righted his friend, who signaled he wanted to ascend. His buddy led him up, but his friend fell behind and then stopped. When the buddy tried to help again, his friend panicked and pulled his buddy’s mask off. The buddy then made a barely controlled ascent, nearly drowning, then descended again for a decompression stop. He saw his friend finning around at 115 feet before becoming inverted again and not breathing. When police recovered his body the next day, he was tangled in his guideline, and his tanks were empty. His dive computer showed several ascents, including one up to 45 feet, before he died. It’s likely that the combo of his poor mental state and profound narcosis led to his death.

The Heavy Load of Obesity

We’ve frequently commented on how obesity is a primary factor in many dive injuries and fatalities: The more weight one packs, the less fit he may be to dive. Obese divers and snorkelers have a larger workload at depth, but especially on the surface.

Take this too-heavy 77-year-old snorkeler on a day trip to a pontoon site on the Great Barrier Reef. He had had coronary bypass surgery and a history of hypertension, but he failed to list his medical conditions when asked at the start of the trip. Though initially calm after entering the water, he was swamped by swells and hit his head on a buoy, causing him to panic and climb onto his buddy. The boat lookout sent out a driver, who grabbed the snorkeler’s hand as he went limp and unconscious, but even with the help of two assistants, he couldn’t lift the obese snorkeler into the boat, so they towed him to the pontoon. CPR did not revive him.

There was a similar case at the Great Barrier Reef the same year, where another obese snorkeler panicked and asked to go back to the boat. The guide steered him toward the approaching tender, but he couldn’t lift himself aboard and went limp. He was too heavy for the driver to haul up, so he was towed 150 feet back to the boat. The captain tried CPR and oxygen (there was no defibrillator aboard) as the boat drove 55 minutes to the nearest island, where a defibrillator got no response.

A question that plagues the industry is whether a dive operator should refuse to let a morbidly obese patron dive. Mainly, if a diver presents medical certification, that’s enough. However, some people haven’t told the truth. A savvy operator suspects the customer just doesn’t have the body to dive, but he takes their business anyway, though in some cases, he may not be doing the diver a favor.

A severely overweight 49-year-old openwater course student received a dive medical clearance from a doctor, who noted her obesity and hypertension, but she failed to tell him about her previous heart and breathing troubles, which would have been disqualifiers. For the first openwater dive, she was with several divers and two instructors, one of which buddied with her. They snorkeled to a buoy 165 feet from shore, but she was too buoyant, so her buddy put an extra six pounds in her BC pocket. Almost immediately after descending, she surfaced and complained of being sick, then started breathing rapidly. Back in the shallows, she took puffs of albutamol, a prescription drug to open up the lung’s airways, but she soon became unresponsive and blue in the face, with frothy sputum coming from her mouth. Paramedics couldn’t find a pulse, and a defibrillator didn’t work. Had she told her doctor her full medical condition, she wouldn’t have been cleared to dive, and she’d still be alive.

--Vanessa Richardson