Why Divers Die: Part I

Do you remember when it was diving that used to be dangerous and sex was safe? It's amazing that with so many dives being done worldwide every year, so few people get killed while doing it. That's the good news from the most recent incident reports published by U.S. and British dive agencies.

Divers Alert Network (DAN) collects dive accidents and fatalities and issues an annual report. For its latest one, of 2015 incidents, DAN observed that American and Canadian recreational scuba fatalities were at a 20-year low. (The British Sub-Aqua Club, which also keeps records for dives in the United Kingdom, came to the same conclusion in its neck of the woods.) Still, 127 fatalities were reported to DAN that year, 43 occurring in U.S. waters. It's no surprise Florida had the most, because it's the state with the most diving activity.

We can put this low rate of attrition down to proper training, good oversight by dive center staff and the application of common sense. But of course, even one fatality is one too many. There are always lessons to be learned from the death of a diver, and since its founding, Undercurrent has published significant dive fatality cases so that readers can better prepare themselves for safer diving. You only dive for pleasure, so why risk your life doing it?

Lost at the Surface

Divers need to be responsible for their own actions, but boat crews also need to be prepared for when things go wrong. As these incidents show, lazy and inept boat crews help to create some worstcase scenarios.

In September 2016, we wrote a story analyzing what went wrong when five divers were lost at sea while diving at remote Malpelo Island. They went into the water as dusk approached, without lights or any surface-signaling devices. The crew of the Colombian-based liveaboard MV Maria Patricia failed to keep a proper lookout, so the divers weren't seen when they surfaced prematurely, and the boat had insufficient fuel to make a search once crew realized the divers were missing.

Remarkably, at the same time this was happening, another group of divers suffered a similar experience on the other side of the globe. Setting off from Mauritius, the group became separated from their boat in rough seas. They were found after many hours, but what was telling was what one diver said later of the crew: "It was like the instructor had no safety training. He had no radio, no SOS equipment, no way of calling for help."

You'd think boat crew would have double- and triple-checks of divers back on the boat down pat, but they're still leaving divers behind in error, too.

Laurel Silver-Valker was a frequent passenger on the Sundiver Express out of Long Beach, California, and was one of the divers on a lobster dive off Ship Rock at Santa Catalina Island on December 29, 2015. She was last seen at 9:35 a.m., descending from the boat to a depth of 15 feet. When the divers returned to the boat, roll was called -- but four divers' names were missing from the roll, including that of Silver-Valker, 45, so those names were not called out. The boat went to another dive site, and it was noon before crew realized she was missing. Up to 30 divers searched for her for more than two weeks, but Silver-Valker was never found. And this isn't the first time the Sundiver Express has left a passenger behind -- in 2010, a court awarded $1.68 million to a Santa Monica man who was abandoned by the Sundiver Express and floated for five hours off the coast of Newport Beach until a boat full of Boy Scouts happened to spot him and scooped him from the sea.

And just last September, a pair of British divers surfaced during late afternoon and were invisible to their dive boat due to the reflection of the sun on the water. The crew called the emergency services, and the lifeboat crew, coming from a different direction, reported that they were easily visible with both marker buoys and flashlight signals as darkness approached. Come on, dive crews, make more of an effort to move the boat around a bit, and scan the waters when your customers are missing.

The Panic that Causes More Problems

European divers tend to dive deep. An analysis of BSAC's 2018 Incident Report indicates that many divers' rapid ascents were due to anxiety or panic. Another high proportion was due to poor buoyancy control from weighting issues or problems with gear, including careless use of a delayed surface marker. And a few were caused by regulator freeflows (in cold freshwater) or divers mismanaging their air supplies.

In the DAN report, a 15-year-old openwater diver who was out of practice went out with a newly certified friend who was making his first dive without an instructor. Panic ensued after one diver ran out of air; they fought over the remaining functioning regulator, and the expected fatal results happened.

Of the 56 reported incidents of decompression illness reported last year in the U.K. (where deco diving is more common), nearly half involved dives deeper than 100 feet, although an equal number appeared to be within the limits of the casualties' computers. Ten percent were a result of a rapid ascent and seven percent involved missed decompression stops.

If an affected diver can get to a hyperbaric facility soon enough, the result of a DCI may not be fatal. However, a rapid ascent can be, and many of those are due to divers overweighting themselves. An inexperienced novice 50-year-old diver, wearing a rented BC and using newly purchased gear, including wetsuit, went diving with too much weight. Combine that with a heavy steel tank and it leads to fatal consequences. Her computer recorded an uneventful dive profile until the 18-minute mark, when a rapid ascent from 41 feet to the surface was followed by an immediate return back to 41 feet. The equipment inspection report concluded that a catastrophic loss of buoyancy was a significant factor in her death.

Sometimes a combination of problems arises. A British instructor teaching a student unknowingly had a breach between the corrugated hose and wing-style BC he was using. He was unable to maintain buoyancy at the surface, and the poor student was unable to keep him there. The divers who recovered the instructor's body reported that his wing was unable to contain any air.

And an instructor can get injured if a student loses buoyancy control. There was a case of that last April, when an instructor suffered a DCI after rapidly ascending with a novice diver in that way.

Not Fit Enough to Dive?

There is always at least one mention every year in the DAN and BSAC reports of unfit and/or obese divers suffering accidents and fatalities. As we get older, we lose muscle tone and often put on pounds of fat where muscle was before. In living the good life, many of us become obese, even morbidly so. The weightlessness of diving can be seductively insidious. But the sudden requirement to fin hard against a current, struggle with full scuba gear through the shallows on a shore dive, or even climbing a boat's steep ladder while fully loaded with weights and tank, can easily cause a heart attack.

A female diver with a body mass index of 43 (anything over a BMI of 30 is considered obese) had difficulty climbing a boat's ladder in rough seas and succumbed to the effort, not responding to CPR. Similarly, a 58-year-old inexperienced male diver with a BMI of 39 and a history of medical problems, including diabetes, but with a medical form signed by a physician, endured a hard surface swim back to the boat and lost consciousness at the ladder. He was lifted onto the boat for CPR, which was unsuccessful. An autopsy revealed extensive narrowing of his coronary arteries, and the cause of death was determined to be atherosclerotic and hypertensive cardiovascular disease.

Then there are the medical conditions that can be exacerbated while diving. A 54-year-old rebreather diver told people before a dive that he was feeling unwell, but thinking it was as a result of the previous night's dinner, he went into the water anyway. The autopsy's main findings included heart disease and plaque-obstructed arteries, so what the diver thought were symptoms of too-rich food were probably related to acute coronary syndrome.

Late last summer, the Coast Guard was called to a bay where a man had been diving solo although he was accompanied by two snorkelers. Apparently, he had been suffering breathing problems for the previous three months and had cotton stuffed in his ears when his doctor advised him to stop diving.

Besides being foolish, divers can also be deceitful, especially when filling out a medical declaration. A woman died while diving with a Bahamas dive outfit, and it was later discovered that she was suffering from terminal lung disease but had falsified her answers on the liability release so that she could "do one last dive. "

Little if any medical research is done regarding the effects of drugs under pressure. A 41-year-old diver with 400 dives under her belt had been prescribed the antidepressant Prozac three years prior to her last and fatal dive. She drowned in a quarry after abandoning her group of four divers and ascending alone. Her body was found later, and an autopsy deduced, rightly or wrongly, that the drug's toxicity was a contributing factor in her death.

The DAN report shows that the largest group of dead divers in the U.S. and Canada were between ages 50 and 69 years -- obviously a dangerous age.

-- Ben Davison

Next month, we'll take a look at more factors -- malfunctioning gear, hyperhydration and running boat engines among them -- that increase divers' fatality risks if they're not careful.