Why Divers Die: Part IV

While the conventional wisdom these days is that divers who attempt to save themselves fare better than those who rely on a buddy, many divers are illequipped to conduct an emergency ascent. Because of perceived liability issues, the training agencies offer little in the way of emergency ascent training during certification, and after certification, few divers practice emergency ascent techniques.

So if a diver faces a situation where an emergency ascent is required, it may be the first one he has ever attempted. Panic often sets in. The diver doesn't adequately exhale or holds his breath. Too often, the result is a fatal embolism.

In reviewing the diver deaths recorded by the Divers Alert Network in their 1997 and 1998 reports, we observed that several emergency ascents led to embolism and death. We offer these few cases in hope that we may each continue to dive safely.

A 40-year-old woman who was a student in an advanced openwater class made a shore entry during a night dive. Her dive was to be of fifteen minutes' duration and to a depth of 95 to 125 feet. However, she got separated from her buddy, ran low on air, and made an emergency ascent. She was found unconscious on the surface after having suffered an embolism and could not be resuscitated.

A 36-year-old male who had an advance certification but was an infrequent diver made a dive to 130 feet. Although he had plenty of air in his tank, he apparently had a regulator problem and began a rapid ascent. A divemaster diving with him restrained him briefly, but he ascended a second time. He was found unconscious on the surface and later died of an embolism.

Sometimes a death from a rapid ascent seems entirely unexplainable. This 26-year-old male diver, a student in an advanced open-water course, dived to 102 feet for a bottom time of twenty-eight minutes along with two other divers. He ascended to a safety stop, where he paused briefly before going directly and rapidly to the surface. On the surface, he was progressively short of breath and was rushed to a chamber, but after three days he was pronounced brain dead. He had 900 psi in his tank. However, his equipment was in poor repair, and he may have had difficulty drawing air at depth.

Sharing air is one way to avoid a free ascent, but it must be done properly. A 32-year-old male with advanced open-water certification and his two buddies made two dives below 100 feet to explore a wreck. On the second dive, he ran out of air and used his dive buddy's octopus. Then the third diver also ran out of air and panicked. All three ascended together using a single shared air source. The ascent from 80 feet was rapid, and the decedent was unconscious at the surface. Although he was treated in a hyperbaric chamber, he died of an embolism.

While a certified diver can have problems with a planned rapid ascent, you can imagine what happened to this 22-year-old uncertified diver who planned an air dive to 300 feet with a group. At 230 feet, she apparently had a seizure and made a rapid ascent, arriving unconscious at the surface. Two other divers in the group were treated for decompression sickness.

While an unplanned ascent can be controlled (see the sidebar), uncontrolled ascents mean trouble. This 37-year-old male was diving on a wreck at 95 feet when he became separated from his buddies. A few moments later a buddy saw him shoot to the surface in an uncontrolled rapid ascent, then sink back down to the bottom unconscious. Death was due to an embolism.

Photographers have to be especially careful about holding their breath. A 32-year-old male with advanced open-water certification made a dive to 90 feet for twenty-five minutes. On the way up he took photographs of two divers at 30 feet. He was found unconscious on the surface shortly afterward and later died of an embolism. This tragic death reminds us of famed underwater photographer Ron Church (no relation to Jim) who was filming in blue water in the 1970s. While holding his breath to still his camera, he rose without any fixed point of reference only to embolize and die.

Sadly, too many divers die after having been struck by boats, in some cases the boat from which they've been diving. In this case, an experienced 49-year-old male diver was ascending just as someone decided to reposition the dive boat. He was struck in the head by the propeller and died instantly. In an other case, a 39-year-old dive instructor who was taking students on an open-water dive entered the water while the propeller was turning and the boat was still moving. He was struck in the head by the propeller, and, although he was assisted back into the boat, he became unconscious and later died in a hospital.

Jet skis are anathema to divers. Those who dive where they're prevalent need dive flags and must use extreme caution. Unfortunately, more and more dive destinations are permitting jet skis. Next time you visit a destination that permits them -- or is considering doing so -- tell them about this 18-year-old woman who was diving with her husband in a lake. They both ran low on air and had to surface. Just as the woman reached the surface, she was struck in the head by a jet ski and died immediately. In another incident, a 50-year-old male who was diving alone was struck by a jet ski while on the surface; he also died, the victim of a hit-and-run accident.

Finally, there are quirky reasons divers die, and a good diver must be prepared for them. Between shore dives, this 34-year-old and his buddies ate a huge meal. On his second dive, he ran low on air and left the group to head back to shore. Upon reaching shore, he stood up, then quickly collapsed. His death was due to aspiration, perhaps from inhaling his own vomit.

As a reminder, if you should become nauseous while diving, vomiting into your regulator is preferable to removing it. However, you must have the presence of mind to clear it of particles before you inhale again.

-- Ben Davison