DIVING

1. Dive Fatalities
12-44: Oxygen sensor failure – drowning due to seizures caused by oxygen toxicity
52-year-old male, experienced technical diver and instructor, was supervising another diver who was working towards
his trimix technical diver certification. Dive buddies witnessed victim experience a seizure at about 17 minutes into the
dive at 160 fsw (48 msw), drop his mouthpiece and lose consciousness. Buddies brought the victim to the surface and
tried to resuscitate him but without success. The investigation report suggests failure of the oxygen sensors as a probable
cause of seizures. The report also indicated the decedent neglected to pre-breathe his CCR unit prior to the dive.
13-11: Regulator free flow and failed gas donation led to asphyxia at depth
55-year-old male, Master Diver certification and experienced. He was diving a shipwreck with a group. His dive buddies
noticed the victim swimming with a free flowing regulator out of his mouth. The victim approached the dive buddies
and signaled towards the bubbles by his chest and pointed over his left shoulder to turn off the valve for the free flowing
regulator, after which one buddy shut off the valve to stop bubbles flowing from the regulator. One of them offered
the victim their primary regulator which the victim attempted to use then returned. The witness described the victim as
“acting like it did not work”. Then the victim stopped moving and the buddies attempted to again put the regulator in his
mouth. When that did not work, and it became clear he was unconscious, they send him to the surface alone from the
depth of 200 fsw (60 msw). First, they tried to inflate his BCD, but then discovered the power inflator was not connected.
They inflated his dry suit instead and sent him to the surface. All other equipment was examined and found to perform
as designed, except for the unattached power inflator. Gas analysis findings came back within standard specifications.
13-78: Drowning (poorly maintained rebreather but unknown why he became unconscious)
38-year-old male, advanced certification and experienced diver. During descent, at 50 fsw (15 msw), victim signaled to
his dive buddies to stop. The victim started to ascend but then lost consciousness and began to sink after a few seconds,
hit his head on a platform and continued to sink. Victim was recovered by his buddies, pulled to the surface and taken to
the hospital where he was pronounced dead. An equipment inspection by the investigating team determined the decedent’s
equipment had multiple deficiencies, including a mechanically non-functional alternative rebreathing device. The
diluent tank had a 39.8% oxygen mixture and it should have been 50% mixture. The system was described as poorly
maintained, O-rings were dry and the oxygen tank may not have been turned on, which could have caused hypoxia
leading to unconsciousness. The victim was known to service his own equipment and a witness statement indicated the
decedent had experienced some O-ring problems a month prior to the incident. How this could have affected the safety
of the rebreather is not clear.
10-77: Unexplained death after treatment for decompression sickness
29-year-old male, instructor level certification and experienced diver who had a medical history of asthma. Dive profile
was a 3 hour dive to a maximum depth of 248 fsw (75 msw). The diver completed the dive without symptoms or issues
but, once back on the boat, complained of nausea and tingling limbs. He told others on the boat he suspected DCS, as
he had on several occasions previously. Soon after, he experienced a seizure that lasted approximately 30 seconds. He
regained consciousness but complained of shortness of breath and dizziness. He was transported to the local emergency
room and later transferred to a hyperbaric chamber for treatment. Post hyperbaric treatment, his condition deteriorated
with increased respiratory distress and he was taken to the emergency room. He became apneic and was pronounced
deceased despite resuscitative efforts.
11-22: Severe decompression sickness - omitted 40 minutes of decompression
64-year-old male, certified and experienced technical diver. The diver ascended from a deep dive of 214 fsw (65 msw)
at a slow and controlled rate, but past his decompression ceiling and missed approximately 40 minutes of computer
indicated decompression. Immediately upon surfacing he was in distress and lost consciousness as the boat crew assisted
him out of the water. He did not regain consciousness. Autopsy findings cite evidence of DCS and AGE.
13-82: Air embolism and asphyxia - ran out of gas
60-year-old male, technical diving certified and experienced. Diver was found unconscious and without a pulse at the
surface following a solo dive. His regulator was still in his mouth upon recovery, however both tanks were empty. According
to the investigation reports, an autopsy revealed his death was due to an air embolism from a rapid ascent and
missed decompression after a dive to a maximum depth of 174 fsw (53 msw). The victim’s dive computer showed he
had a rapid ascent from approximately 80 fsw (24 msw). A post-incident equipment inspection determined that the tanks
on the rebreather were empty and the oxygen tank was shut off. The bailout tank was also empty and the regulator of
that tank had not been deployed.
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Annual Diving Report – 2012-2015 Edition