Why Divers Die

Why do divers die? It’s easy to say the cause was an embolism, a heart attack, or some such thing. However, behind nearly every diver death is an error, a fatal error, made by the diver himself.

So that we may better understand why divers die, we occasionally analyze case reports from DAN, the South Pacific Underwater Medical Society, and other sources. We share the results with you, our readers, so that you may see the unique errors that occur and hopefully learn from the tragic examples of our fellow divers. This series covers DAN’s 1997 deaths and South Pacific deaths released in the SPUMS Journal in 1998.

In reviewing dive deaths, each year we find people who flat-out run out of air and then drown. While often there is a prior event, such as getting entrapped, here we report cases where an empty tank due to the diver’s neglect brings his comeuppance.

This case of a 28-year-old experienced diver is fraught with error. He and his buddy made a shallow dive but ran out of air and surfaced far from the boat. On the swim back to the boat, he became extremely fatigued, so his buddy continued without him, expecting to return with the boat to pick him up. However, he had difficulty starting the boat and lost sight of the decedent, who was only 75 yards away. When he got there, his buddy had disappeared. They found the body two days later. The decedent still had his weight belt on but had removed his BC.

While the errors during the dive are obvious, there is a precipitating factor: the diver was not in sufficiently good shape to handle a long surface swim. Either he had insufficient aerobic conditioning to handle the work of breathing or insufficient leg strength to kick to the boat. How do you measure up?

Here’s another case of a diver’s fatal error. This 53-year-old male made a series of dives with short surface intervals without changing his tank. At the end of the last dive, with no air in his tank, he struggled on the surface and was unable to swim back to the boat. Despite being rescued by other divers, he lost consciousness and drowned. An autopsy revealed an 80 percent narrowing of a coronary artery, which severely restricted blood flow under stress.

What’s with this undertaking dives with less than a full tank of air? This 26-year-old male made an initial dive to 30 feet with three other divers, then made a second to 100 feet with only 1500 psi of air. He returned to the surface to remove his hood, then rejoined the group but soon got separated and began to sink to the bottom. He struggled with a diver who attempted to help him. He drowned and they recovered his body 24 hours later.

It’s one thing to breathe a tank dry when you’re in twenty feet of clear water under your dive boat, and quite something else to do it in the middle of the Sulu Sea when a tinny has to pick you up. If you’ve been on live-aboards, no doubt you’ve seen a jerk or two who habitually breathe their tanks dry. They’re usually experienced divers, as was this 35-year-old male who made a habit of using every bit of air in his tank before ending a dive. Five years previously he had suffered a severe case of spinal cord DCS that resulted in partial paralysis, but it did not seem to affect his movement in the water. So he continued to dive, albeit incautiously. On a night dive, he and his buddy dropped to 115 fsw, then went separate ways as they had previously agreed. But he did not return. When they recovered his body 16 hours later, his tank was bone dry.

While his buddy might have helped him out of the pickle, buddy-breathing is not a panacea. This 62-year-old experienced diver ran out of air while making a dive to 108 fsw on a wreck. He was buddy-breathing with another diver when that diver ran out of air as well. Another came to their assistance, but the decedent would not let go of the anchor line and refused an alternate air source when it was offered. He became unconscious and was brought to the surface. He had drowned.

This Australian case demonstrates a problem with the buddy system when both divers run low and one decides to go elsewhere for air. The victim, who had made about 20 dives, was paired with a more experienced diver for a dive to a wreck at 90 feet. The current was significant. Although his buddy could swim forward without holding onto the wreck, the victim needed to pull himself along. When they reached the bow, the buddy had only 600 psi, so he ascended toward the line. The victim, however, descended to other divers, an instructor, his 15- year old son, and an inexperienced diver. The victim tapped the boy on the shoulder and indicated he wished to buddybreathe; the boy (though he had an octopus) signaled to his father that a diver wanted air. The father looked but failed to see the victim, although he saw the victim’s buddy, who showed him his gauge. Because he seemed to have sufficient air for a safe ascent, the divers watched him ascend. The boy, however, saw the victim lying on the sea bed a short distance away, regulator out of his mouth and gasping. Unfortunately, this did not seem remarkable to the boy, so he did not attract his father’s attention. The body was found later on the sea bed.

Bad Conditions

When the surf is up, shore diving can present serious entrance and exit problems. I remember my very first dive after certification, when by buddy and I clamored through a rough surf at Monterey’s Monastery Beach. As soon as I got underwater, I raised my camera to photograph her, not realizing that she had lost her regulator. In fact, she had temporarily dislocated her shoulder and tried to get my attention, while I bounced around in the surf trying to get my shot. Realizing I wasn’t paying attention, she shot about ten feet to the surface for fresh air. Getting out of the surf was a struggle for both of us. Thankfully, I didn’t lose my buddy. I did lose my camera.

This Aussie, who was diving with two relatively inexperienced 16-year-olds, wasn’t so lucky. Choosing a sheltered side of the point to enter, the two youths backed into the water, but the victim walked directly ahead. A large wave knocked down all three, washing the two boys back on the beach. They removed their gear, then went to high ground to look for him but couldn’t see him. His body was recovered later.

Waves are dangerous on entry, but they are also dangerous on exit. After this diver and his buddy completed a shore dive, they exited, climbing up a rocky ledge. A large wave hit them, pushing one diver against the rocks, where he hit his head, then swept him off the ledge.

And let’s consider sand, another shore-diving hazard. This Australian woman had made about 20 dives, but this was to be her first surf entry. She got into trouble, eventually falling unconscious. Her buddy attempted to inflate her BC but it vented as fast as he filled it. (Upon examination, sand was found clogging the BC oral-inflation device; the sand probably entered the valve at the conclusion of the previous dive and she had not washed it out.) He was unable to ditch her weight belt because her small size caused the BC to cover her belt. Despite inflating his own BC, he lacked sufficient buoyancy to bring her to the surface because he failed to ditch his own weights. He towed her back underwater, but she died two days later without recovering consciousness.

A Cautionary Note

Many readers of Undercurrent were certified in warm and calm waters and today dive in sanitized and supervised situations from resort boats. Should you decide to tackle different conditions, shore entry and exits, for example, dive with someone who knows the conditions and can teach you how to handle them.

— Ben Davison