Dont think this has been posted here... terrible accident but leasons to learn as well.
-----Original Message-----
From: Sawatzky, David
Sent: October 4, 2002 8:54 AM
To: inspiration@drogon.net
Subject: CCR1000 fatality, Michel Guerin, Accident Report
Fellow Inspiration Owners,
I am sending this accident report to the list as there are several lessons
we can all learn from it. Would someone please cross-post it to the
rebreather list? I am not a member and do not wish to become a member of
the rebreather list (too many emails already) . If this is listed twice,
my apologies but I don't think it worked when I tried to post it yesterday.
David
Dr. David Sawatzky
Consultant in Diving / Aviation Medicine
DRDC Toronto (formerly DCIEM)
(Defence Research and Development Canada)
Note new email address: 'David.Sawatzky@drdc-rddc.gc.ca'
CCR1000 Fatality Report, Michel Guerin, 18 May 2002 (report written 26 Sept
2002)
The following is my personal report of the death of my friend Michel
Guerin,
and does not represent the official views of any organization. However, I
have had access to the findings of the autopsy, coroner's report, police
report, and the equipment evaluation. Michel's wife Linda has approved the
release of this report so that other rebreather divers can learn from this
tragedy and hopefully prevent their own deaths.
Michel was a very bright, fit, healthy, 42 year old, highly experienced
technical diving instructor. He was meticulous in the care of his gear and
in his diving techniques. Michel had been diving the CCR1000 for
approximately 6 years and had extensive experience, including many dives
down to 330 fsw (100 meters). He was extremely knowledgeable about
rebreathers (he also owned and dived a Drager SCR) and in the fall of 2001
he gave a fantastic presentation on rebreathers to approximately 100 people
at Underwater Canada in Toronto. I was to have given the talk but a work
trip came up and I asked Michel if he would give the talk for me. At the
last minute my work trip was cancelled and I was able to attend the talk.
Michel did an excellent job and there is no question that he understood
rebreathers completely.
Michel was working for a bank, doing a Master's degree, as well as his
numerous other activities. He had been very busy all winter and spring
(normal for him) and the dive on which he died was his first dive of the
year. We know the following facts.
- On 18 May 2002 Michel and two friends went for a shore dive at
Tobermory, Ontario. Michel invited me to dive with him that day but I was
flying to Grand Cayman to teach two basic Inspiration CCR students and had
to decline.
- All three divers were quite experienced and all knew the dive
site
extremely well
- Michel was diving the CCR1000 while the other two divers were on
OC twin sets
- All three divers were planning shallow, simple, gear sorting out
dives (one checking out a new twin set, the second his new digital
underwater camera, and Michel was doing his first CCR1000 dive of the year,
'just to get in the water')
- The dives were planned as 'semi-solo', i.e. same place, same time
but fairly independent
- The divers entered the water at approximately the same time
- One diver was attempting to tie the dive flag to a rock on the
bottom at 20 fsw depth and Michel swam over and tied the line off for him.
The divers then separated. This was two minutes into the dive (easily seen
on the profile downloaded from Michel's dive computer).
- Friends on the surface saw a large number of bubbles from where
Michel was diving several minutes into the dive. They could also see the
bubbles from the other two divers a fair distance away, one to the right
and
the other to the left of where Michel was. The bubbles continued for a few
minutes, Michel surfaced briefly and then went back down. The bubbles
stopped and the people on the surface assumed all was well as they knew
that
rebreathers were not supposed to make bubbles.
- Approximately 14 minutes into the dive, the diver with the camera
saw Michel lying on his back in approximately 20 fsw and took some
pictures.
He thought Michel waved and that he was goofing around. The mouthpiece was
out of Michel's mouth and there were bubbles coming out of the set (the
diver with the camera was not knowledgeable about rebreathers). The diver
then swam away, taking more pictures of the bottom.
- The diver with the camera saw Michel again 24 minutes into the
dive. He became concerned as Michel had not moved since he had seen him
approximately 10 minutes earlier. Michel was still lying on his back,
mouthpiece out of his mouth and now there was no gas coming out of the
rebreather. The diver shook Michel but he was unresponsive. The diver
then
inflated Michel's drysuit and brought him to the surface. There was no
pulse nor respiration, CPR and resuscitation were attempted but Michel was
dead.
- Autopsy showed a small arterial gas embolism in the brain
- Michel's dive computer (one data point every 20 seconds) showed
that he stopped briefly at 20 fsw (minute 1:40 to 2:20, this is almost
certainly when he tied off the line to the dive flag). He then descended
to
a maximum depth of 41 fsw at minute 4:00. He slowly ascended to 30 fsw by
minute 6:00 and stopped there for approximately 40 seconds (minute 6:00 to
6:40). Michel then rapidly ascended to 7 fsw (minute 7:40) and dropped
back
down to 22 fsw (minute 8:40). He stayed at that depth for 60 seconds and
then rapidly ascended to 2 fsw (minute 11:00, he almost certainly surfaced
and sank before the next data point at 5 fsw 20 seconds later). Michel
then
sank to 16 fsw (minute 11:40) and the depth remains absolutely constant
until minute 25 when he was sent to the surface (minute 26:00) by the other
diver who inflated Michel's drysuit.
- Equipment: CCR1000 with two onboard tanks (air and O2), drysuit
with a bottle of gas to inflate the drysuit, BC with a second bottle of gas
to inflate the BC. Neither off board tank had a second stage regulator
attached. The CCR1000 was designed to maintain a PO2 of 0.7 ata. This set
had almost certainly been 'adjusted' to maintain a PO2 of 1.2 ata. The
CCR1000 also has an on/off switch to turn off the electronics (you can not
attain a PO2 of 1.2 ata on the surface). Common practice with the CCR1000
is to setup the rig and then either turn off the electronics, or turn off
the O2 bottle until the diver is deep enough for the set to be able to
maintain a PO2 of 1.2 ata. After the dive, the diluent bottle in the
CCR1000 was empty. The O2 bottle still contained 1,750 psi of O2. The
other
two tanks still contained gas. The attachment of the inhalation hose to
the
mouthpiece was loose and on one of the pictures taken during the dive,
Michel can be seen lying on his back, mouthpiece out of his mouth with the
loop floating above him. Gas is escaping from the junction of the
inhalation hose with the mouthpiece and NOT from the mouthpiece itself.
The
design of the CCR1000 is such that if you are lying on your back with the
mouthpiece out and open, diluent is continuously injected into the
breathing
loop.
Those are the facts. The following is conjecture.
Michel could have turned off the electronics or the O2 bottle on the
surface
(standard procedure) and forgotten to turn them on in the water, becoming
hypoxic several minutes into the dive and loosing consciousness. Although
the timing of the events is appropriate for this scenario, this possibility
is seen as unlikely for the following reasons. Michel was very experienced
to make such a simple and stupid mistake (but many highly experienced
divers
have). This scenario requires Michel to fail to check his PO2 for the
first
7 minutes of the dive. As this was his first dive of the season, it would
be more likely that he would be paying MORE attention to the PO2 than
normal, not less. More importantly, this scenario does not fit the dive
profile downloaded from Michel's dive computer. If he became hypoxic he
would either have lost consciousness or realized he had a problem and tried
to ascend to the surface. As he ascended, the PO2 would have dropped
further and he would have definitely passed out, sank and died. However,
he
had his problem at 30 fsw ascended to 7 fsw and sank back to 22 fsw. Sixty
seconds later he again attempts to reach the surface. Waking up after you
lose consciousness, when the PO2 in the set would be continuing to
decrease,
is not seen as likely. The scenario is also not a good explanation for the
large number of bubbles seen on the surface.
Michel could have lost control of his buoyancy, shot to the surface,
panicked, held his breath, embolized, lost consciousness, and sank. I also
believe this is highly unlikely as Michel was VERY experienced and thus not
likely to have died from such a basic and easily controlled problem. In
addition, it also does not explain the two attempts to reach the surface.
Finally, although the ascents were rapid, they were not 'out of control'.
My personal belief is that something like the following happened. Michel
was having a perfectly normal dive, the set was working fine and all was
well. He was ascending back up the rock face and 7 minutes into the dive,
at a depth of 30 fsw, he turned his head to look at something and the
inhalation hose started to leak badly at the mouthpiece, letting gas out
and
a lot of water in. Michel suddenly started getting a lot of water every
time he tried to take a breath. He almost always dived with a stage bottle
but on this simple, shallow dive he did not have any other source of
breathing gas but the loop on the CCR1000 (no OC diluent option such as is
standard on the Inspiration nor bailout bottle).
After approximately 30 seconds of trying to solve the problem on the
bottom,
Michel decides that he has to get to the surface so he inflates his drysuit
and starts to ascend. He makes it to 7 fsw or less over the next minute
and
then descends to 22 fsw. I believe Michel used his drysuit (instead of his
BC) for buoyancy because this is a very bad habit that most cold water
drysuit divers have (including me until 2 years ago when I had an
'incident'
that taught me the error of this practice). The reason drysuit divers
often
do this is that if you have the correct amount of weight, keeping a
comfortable amount of gas in the drysuit will also keep you neutrally
buoyant (especially with a membrane suit). Therefore, you never use the BC
on a normal dive. When an emergency situation arises, you will go for the
drysuit inflate valve on reflex (you are not even sure where the BC inflate
valve is as you have not used it for months/years!).
The problem in this situation is that the loop on the CCR1000 was filling
with water (because of the leak) and Michel was becoming very negative. It
would have taken a lot of gas in the drysuit to ascend. I suspect the
drysuit burped gas out the neck seal, causing Michel to sink back to the
bottom.
Michel then spends 60 seconds on the bottom, probably in an only partially
functional state before making another attempt to get to the surface. This
time the computer shows he made it to at least 2 fsw. I expect he briefly
surfaced and then sank. Forty seconds later Michel was back at 16 fsw
depth
and the profile goes flat line.
On one of the two ascents, Michel embolized. I suspect he was having more
and more difficulty as he was getting mostly water when he tried to inhale
and that the second attempt to make the surface, in a semiconscious state,
resulted in the embolism, loss of consciousness, and eventual drowning in
16
fsw.
Lessons learned:
If Michel had a buddy, knowledgeable in CCR diving who was actually with
him
when his set malfunctioned, he would probably have survived. A buddy who
was not knowledgeable in CCR diving would also probably have been able to
assist but they might not have noticed that Michel was in trouble until too
late, and then not known what to do.
If Michel had an OC gas option that he could have switched to when his set
malfunctioned, he would definitely have survived if the problem was the
leak. If the problem was hypoxia, he may very well have passed out before
he noticed the problem.
If Michel had been in the habit of using his BC for buoyancy instead of his
drysuit, he would have arrived at and stayed on the surface on his first
attempt. The back mounted wing style BC he was wearing and the back
mounted
counterlung of the CCR1000 would have most likely floated him face down.
However, there were friends and other divers on shore and he would have
surfaced relatively close to shore so I'm sure they would have got his head
out of the water quite quickly and he would most likely have survived.
This was an unfortunate and totally unnecessary fatality. I suspect Michel
was frustrated and angry just before he lost consciousness, knowing that he
was going to die from such a preventable situation. I hope this convinces
all rebreather divers of the absolute necessity of having an OC option,
even
on very shallow dives, for those rare occasions when the loop is lost.
Dr. David Sawatzky
Consultant in Diving and Aviation Medicine
IANTD International Board of Advisors
IANTD Inspiration Trimix Instructor
-----Original Message-----
From: Sawatzky, David
Sent: October 4, 2002 8:54 AM
To: inspiration@drogon.net
Subject: CCR1000 fatality, Michel Guerin, Accident Report
Fellow Inspiration Owners,
I am sending this accident report to the list as there are several lessons
we can all learn from it. Would someone please cross-post it to the
rebreather list? I am not a member and do not wish to become a member of
the rebreather list (too many emails already) . If this is listed twice,
my apologies but I don't think it worked when I tried to post it yesterday.
David
Dr. David Sawatzky
Consultant in Diving / Aviation Medicine
DRDC Toronto (formerly DCIEM)
(Defence Research and Development Canada)
Note new email address: 'David.Sawatzky@drdc-rddc.gc.ca'
CCR1000 Fatality Report, Michel Guerin, 18 May 2002 (report written 26 Sept
2002)
The following is my personal report of the death of my friend Michel
Guerin,
and does not represent the official views of any organization. However, I
have had access to the findings of the autopsy, coroner's report, police
report, and the equipment evaluation. Michel's wife Linda has approved the
release of this report so that other rebreather divers can learn from this
tragedy and hopefully prevent their own deaths.
Michel was a very bright, fit, healthy, 42 year old, highly experienced
technical diving instructor. He was meticulous in the care of his gear and
in his diving techniques. Michel had been diving the CCR1000 for
approximately 6 years and had extensive experience, including many dives
down to 330 fsw (100 meters). He was extremely knowledgeable about
rebreathers (he also owned and dived a Drager SCR) and in the fall of 2001
he gave a fantastic presentation on rebreathers to approximately 100 people
at Underwater Canada in Toronto. I was to have given the talk but a work
trip came up and I asked Michel if he would give the talk for me. At the
last minute my work trip was cancelled and I was able to attend the talk.
Michel did an excellent job and there is no question that he understood
rebreathers completely.
Michel was working for a bank, doing a Master's degree, as well as his
numerous other activities. He had been very busy all winter and spring
(normal for him) and the dive on which he died was his first dive of the
year. We know the following facts.
- On 18 May 2002 Michel and two friends went for a shore dive at
Tobermory, Ontario. Michel invited me to dive with him that day but I was
flying to Grand Cayman to teach two basic Inspiration CCR students and had
to decline.
- All three divers were quite experienced and all knew the dive
site
extremely well
- Michel was diving the CCR1000 while the other two divers were on
OC twin sets
- All three divers were planning shallow, simple, gear sorting out
dives (one checking out a new twin set, the second his new digital
underwater camera, and Michel was doing his first CCR1000 dive of the year,
'just to get in the water')
- The dives were planned as 'semi-solo', i.e. same place, same time
but fairly independent
- The divers entered the water at approximately the same time
- One diver was attempting to tie the dive flag to a rock on the
bottom at 20 fsw depth and Michel swam over and tied the line off for him.
The divers then separated. This was two minutes into the dive (easily seen
on the profile downloaded from Michel's dive computer).
- Friends on the surface saw a large number of bubbles from where
Michel was diving several minutes into the dive. They could also see the
bubbles from the other two divers a fair distance away, one to the right
and
the other to the left of where Michel was. The bubbles continued for a few
minutes, Michel surfaced briefly and then went back down. The bubbles
stopped and the people on the surface assumed all was well as they knew
that
rebreathers were not supposed to make bubbles.
- Approximately 14 minutes into the dive, the diver with the camera
saw Michel lying on his back in approximately 20 fsw and took some
pictures.
He thought Michel waved and that he was goofing around. The mouthpiece was
out of Michel's mouth and there were bubbles coming out of the set (the
diver with the camera was not knowledgeable about rebreathers). The diver
then swam away, taking more pictures of the bottom.
- The diver with the camera saw Michel again 24 minutes into the
dive. He became concerned as Michel had not moved since he had seen him
approximately 10 minutes earlier. Michel was still lying on his back,
mouthpiece out of his mouth and now there was no gas coming out of the
rebreather. The diver shook Michel but he was unresponsive. The diver
then
inflated Michel's drysuit and brought him to the surface. There was no
pulse nor respiration, CPR and resuscitation were attempted but Michel was
dead.
- Autopsy showed a small arterial gas embolism in the brain
- Michel's dive computer (one data point every 20 seconds) showed
that he stopped briefly at 20 fsw (minute 1:40 to 2:20, this is almost
certainly when he tied off the line to the dive flag). He then descended
to
a maximum depth of 41 fsw at minute 4:00. He slowly ascended to 30 fsw by
minute 6:00 and stopped there for approximately 40 seconds (minute 6:00 to
6:40). Michel then rapidly ascended to 7 fsw (minute 7:40) and dropped
back
down to 22 fsw (minute 8:40). He stayed at that depth for 60 seconds and
then rapidly ascended to 2 fsw (minute 11:00, he almost certainly surfaced
and sank before the next data point at 5 fsw 20 seconds later). Michel
then
sank to 16 fsw (minute 11:40) and the depth remains absolutely constant
until minute 25 when he was sent to the surface (minute 26:00) by the other
diver who inflated Michel's drysuit.
- Equipment: CCR1000 with two onboard tanks (air and O2), drysuit
with a bottle of gas to inflate the drysuit, BC with a second bottle of gas
to inflate the BC. Neither off board tank had a second stage regulator
attached. The CCR1000 was designed to maintain a PO2 of 0.7 ata. This set
had almost certainly been 'adjusted' to maintain a PO2 of 1.2 ata. The
CCR1000 also has an on/off switch to turn off the electronics (you can not
attain a PO2 of 1.2 ata on the surface). Common practice with the CCR1000
is to setup the rig and then either turn off the electronics, or turn off
the O2 bottle until the diver is deep enough for the set to be able to
maintain a PO2 of 1.2 ata. After the dive, the diluent bottle in the
CCR1000 was empty. The O2 bottle still contained 1,750 psi of O2. The
other
two tanks still contained gas. The attachment of the inhalation hose to
the
mouthpiece was loose and on one of the pictures taken during the dive,
Michel can be seen lying on his back, mouthpiece out of his mouth with the
loop floating above him. Gas is escaping from the junction of the
inhalation hose with the mouthpiece and NOT from the mouthpiece itself.
The
design of the CCR1000 is such that if you are lying on your back with the
mouthpiece out and open, diluent is continuously injected into the
breathing
loop.
Those are the facts. The following is conjecture.
Michel could have turned off the electronics or the O2 bottle on the
surface
(standard procedure) and forgotten to turn them on in the water, becoming
hypoxic several minutes into the dive and loosing consciousness. Although
the timing of the events is appropriate for this scenario, this possibility
is seen as unlikely for the following reasons. Michel was very experienced
to make such a simple and stupid mistake (but many highly experienced
divers
have). This scenario requires Michel to fail to check his PO2 for the
first
7 minutes of the dive. As this was his first dive of the season, it would
be more likely that he would be paying MORE attention to the PO2 than
normal, not less. More importantly, this scenario does not fit the dive
profile downloaded from Michel's dive computer. If he became hypoxic he
would either have lost consciousness or realized he had a problem and tried
to ascend to the surface. As he ascended, the PO2 would have dropped
further and he would have definitely passed out, sank and died. However,
he
had his problem at 30 fsw ascended to 7 fsw and sank back to 22 fsw. Sixty
seconds later he again attempts to reach the surface. Waking up after you
lose consciousness, when the PO2 in the set would be continuing to
decrease,
is not seen as likely. The scenario is also not a good explanation for the
large number of bubbles seen on the surface.
Michel could have lost control of his buoyancy, shot to the surface,
panicked, held his breath, embolized, lost consciousness, and sank. I also
believe this is highly unlikely as Michel was VERY experienced and thus not
likely to have died from such a basic and easily controlled problem. In
addition, it also does not explain the two attempts to reach the surface.
Finally, although the ascents were rapid, they were not 'out of control'.
My personal belief is that something like the following happened. Michel
was having a perfectly normal dive, the set was working fine and all was
well. He was ascending back up the rock face and 7 minutes into the dive,
at a depth of 30 fsw, he turned his head to look at something and the
inhalation hose started to leak badly at the mouthpiece, letting gas out
and
a lot of water in. Michel suddenly started getting a lot of water every
time he tried to take a breath. He almost always dived with a stage bottle
but on this simple, shallow dive he did not have any other source of
breathing gas but the loop on the CCR1000 (no OC diluent option such as is
standard on the Inspiration nor bailout bottle).
After approximately 30 seconds of trying to solve the problem on the
bottom,
Michel decides that he has to get to the surface so he inflates his drysuit
and starts to ascend. He makes it to 7 fsw or less over the next minute
and
then descends to 22 fsw. I believe Michel used his drysuit (instead of his
BC) for buoyancy because this is a very bad habit that most cold water
drysuit divers have (including me until 2 years ago when I had an
'incident'
that taught me the error of this practice). The reason drysuit divers
often
do this is that if you have the correct amount of weight, keeping a
comfortable amount of gas in the drysuit will also keep you neutrally
buoyant (especially with a membrane suit). Therefore, you never use the BC
on a normal dive. When an emergency situation arises, you will go for the
drysuit inflate valve on reflex (you are not even sure where the BC inflate
valve is as you have not used it for months/years!).
The problem in this situation is that the loop on the CCR1000 was filling
with water (because of the leak) and Michel was becoming very negative. It
would have taken a lot of gas in the drysuit to ascend. I suspect the
drysuit burped gas out the neck seal, causing Michel to sink back to the
bottom.
Michel then spends 60 seconds on the bottom, probably in an only partially
functional state before making another attempt to get to the surface. This
time the computer shows he made it to at least 2 fsw. I expect he briefly
surfaced and then sank. Forty seconds later Michel was back at 16 fsw
depth
and the profile goes flat line.
On one of the two ascents, Michel embolized. I suspect he was having more
and more difficulty as he was getting mostly water when he tried to inhale
and that the second attempt to make the surface, in a semiconscious state,
resulted in the embolism, loss of consciousness, and eventual drowning in
16
fsw.
Lessons learned:
If Michel had a buddy, knowledgeable in CCR diving who was actually with
him
when his set malfunctioned, he would probably have survived. A buddy who
was not knowledgeable in CCR diving would also probably have been able to
assist but they might not have noticed that Michel was in trouble until too
late, and then not known what to do.
If Michel had an OC gas option that he could have switched to when his set
malfunctioned, he would definitely have survived if the problem was the
leak. If the problem was hypoxia, he may very well have passed out before
he noticed the problem.
If Michel had been in the habit of using his BC for buoyancy instead of his
drysuit, he would have arrived at and stayed on the surface on his first
attempt. The back mounted wing style BC he was wearing and the back
mounted
counterlung of the CCR1000 would have most likely floated him face down.
However, there were friends and other divers on shore and he would have
surfaced relatively close to shore so I'm sure they would have got his head
out of the water quite quickly and he would most likely have survived.
This was an unfortunate and totally unnecessary fatality. I suspect Michel
was frustrated and angry just before he lost consciousness, knowing that he
was going to die from such a preventable situation. I hope this convinces
all rebreather divers of the absolute necessity of having an OC option,
even
on very shallow dives, for those rare occasions when the loop is lost.
Dr. David Sawatzky
Consultant in Diving and Aviation Medicine
IANTD International Board of Advisors
IANTD Inspiration Trimix Instructor
