Unlike mass-market dive magazines
that shy away from the topic of
dive accidents and deaths, Undercurrent
regularly reports on such case
studies. Since many dive accidents
occur because the diver made a critical
error, we want our readers to be
forewarned so that you don't become a
statistic.
The good news is that dive deaths are
  declining. 57 American divers died in
  1997, down from 85 in 1996 and 104 in
  1995. That’s a dramatic reduction from
  mid-70s highs that occasionally exceeded
  140 deaths per year. 
In this first installment of our
  series, we’ll focus on dive deaths
  attributable to embolism and boating
  accidents. Most cases cited will come
  from the Diver’s Alert Network 1997
  case studies. All editing and commentary
  are solely ours. 
_________________
While “the bends” gets plenty
  of press as a killer of divers, it’s
  rare indeed when a sport diver
  dies from the bends. Embolism is
  the killer, bends the injurer. For
  example, in the 57 American dive
  fatalities in 1997, only one was
  attributable to the bends. However,
  out of 972 injury cases, 820
  were attributable to the bends, 68
  to embolism (and 84 uncertain).  
When DCS does result in
  death, the victim usually succumbs
  to complications of a
  prolonged hospitalization and the
  multiple medical problems that
  accompany the process (e.g.,
  respiratory distress syndrome,
  pulmonary embolism, etc.).
  However, in the single fatality in
  1997, the diver died of severe DCS
  shortly after completing his dives.  
While the deceased was a very
  experienced male, age 48, his
  dives were indeed unwise. He
  made seven consecutive dives to
  an average depth of 90 fsw, staying
  down in most cases until he was
  low on air. Spearfishing, he had
  found a mother lode of game fish.
  He dived alone, while a nondiver
  waited in the boat, which had no
  radio. After the dives, he didn’t
  feel well, so he reentered the
  water to “decompress.” Barely able
  to get back into the boat, he asked
  the other person to head back to
  shore. With the assistance of the
  U.S. Coast Guard, he was taken to
  a recompression chamber, where
  he died.  
While embolism usually kills
  the inexperienced who run out of
  air and panic, in 1997 many of the
  12 divers who succumbed to an
  embolism were experienced. In
  one case a 38-year-old male, a
  longtime diver, joined two others
  in making three dives below 140'.
  During the ascent from the third
  dive, he stayed below the other two
  after they agreed to ascend. When
  the two began their safety stops he
  was already at the surface, where he
  died shortly afterwards.  
An experienced 58-year-old
  male was making his second dive
  of the day to 91 fsw. During the
  first dive, he ran out of air and
  needed to buddy-breathe. On the
  second dive, he entered the water
  with two other divers, neither of
  whom was designated as his
  buddy. At the completion of the
  second dive, he was seen on the
  surface, apparently doing well,
  but soon he appeared to be
  disoriented, then lost consciousness.
  He died en route to a facility
  with a recompression chamber. As
  it turned out, his tank from the
  second dive was empty, as was the
  tank from the first dive. No doubt
  he rushed to the surface when he
  had problems breathing. While
  the diver was experienced,
  running out of air was an unnecessary
  and foolish act.  
A 33-year-old male diver with
  two years of experience and
  divemaster certification was at 190
  feet with three other divers. While
  apparently having equipment problems, he lost consciousness.
The other divers unsuccessfully
attempted buddy breathing with
him, then inflated his buoyancy
compensator, sending him to the
surface in an uncontrolled ascent.
He died of pulmonary
barotrauma.
A 47-year-old experienced
  male, who dived to 95 fsw without
  a buddy, returned to the boat. He
  reported he had seen a shark,
  panicked, and made a rapid
  ascent. He soon lost consciousness
  and could not be resuscitated.  
When some divers panic, they
  get rid of their regulators. It’s a
  panic reaction that was first
  observed among firefighters
  breathing from oxygen tanks while
  fighting fires. Divers often react
  similarly. A 25-year-old student in
  an initial open water course was
  making his last dive before
  certification. During emergency
  ascent training from 20 feet he
  spit out his regulator. He was
  confused and disoriented on the
  surface, complained of numbness,
  and rapidly lost consciousness.
  Resuscitation efforts were unsuccessful.  
In this case, the deceased was
  a 36-year-old male who had made
  less than 20 dives. After an initial
  dive to 82 fsw, he and his buddy
  made a second dive to 130 fsw. He
  seemed to have problems with his
  gear, then ascended rapidly. His
  buddy helped him on the boat
  and called for assistance. He was
  airlifted to a medical facility, but
  he died en route.  
Every year, it seems, fathers
  contribute to the deaths of their
  untrained sons. In this case, a 12-
  year-old boy had no formal dive
  training but had made a dozen
  dives with his father. Sometimes
  he used his own regulator, but
  often he would descend and share
  an air source with his father. On
  this dive, he went to twenty feet,
  sharing his father’s air. The boy
  surfaced with his father directly
  behind him, but unbeknownst to
  his father held his breath. He
  screamed upon reaching the
  surface, lost consciousness, and
  died.  
In 1997, three divers lost their
  lives when hit by a boat, two when
  a running boat propeller hit their
  heads — or their heads hit a
  running boat propeller.  
This 39-year-old male had
  made 30 lifetime dives but none
  in the past three years. He entered
  the water with his girlfriend, but
  when she did not descend with
  him he returned to the surface.
  She had panicked and required
  assistance from the boat crew to
  get her into the boat. The crew
  did not see her buddy, so they
  assumed that he had descended to
  join the group. When he was
  missing after the dive, they
  searched, finding his body four
  hours later. He had a blunt
  trauma to the head, presumably
  caused by contact with the boat in
  rough seas.  
This 26-year-old male was an
  experienced and frequent diver.
  He made a short, shallow dive, but
  surfaced far from his dive flag. As
  he hit the surface, a powerboat
  struck him and caused severe
  injuries. They pronounced him
  dead at a local hospital.  
A 71-year-old female certified
  diver had a fair amount of experience
  but had not been diving
  during the previous year. As she
  was completing her second dive of
  the day, she was ascending when
  the boat operator, who had been
  moving around to pick up a diver,
  put the boat into gear. She
  ascended directly into the propeller.
  It killed her instantly.  
In this case, of course, the
  boat captain has a share of the
  blame. However, it raises an
  extreme cautionary note to divers
  — never, ever, surface near a
  propeller, even if the engine is not
  running.
 — Ben Davison