Rob Davie's accident. (aka. BigJetDiver)

[ScubaTexan]

You know, I had a wild thought driving home today and thinking about this. It occurred to me that I could think of a medical condition that would first make you short of breath (feel very much like a scrubber failure) and then cause a cardiac arrest, and furthermore, is something that someone who's just flown to the Red Sea would be at significant risk for -- a pulmonary embolus. I've seen a number of patients coming in with shortness of breath after a trans-oceanic flight and proving to have a PE. Big PEs can be lethal. This would essentially fit everything we know -- Rob would have felt short of breath and suspected the loop, switched to bailout (which wouldn't have helped very much) and initiated a rapid ascent because it was clear that something was very wrong. Even if he reached the surface and began swimming, another clot or shifting of the original one could cause cardiac arrest. Such a patient is generally not resuscitatable.

A WAG, but something that fits all the known facts.

This seems to be as feasible a possible COD as anything I've seen so far. And I do believe this would show up in an autopsy, IF one has been done, either in Egypt or back home.

 

[Cacia]

someone suggested I edit out David Bloom's name. This was a major news story on all networks, as was his cause of death....so whatever ya'll think.

 

[scubapolly]

Catherine,
I don't think it is necessary to edit out the name. Not only was it a major news story when it happened, but his widow has gone on to use his name and his story to get the word out about PEs.
I think while this is technically in violation of the rules of this forum, but I think all would agree it is common knowledge and does not violate the spirt of the rules.
After all we are discussing "Rob Davie's accident" rather than "The rebreather death of he who cannot be named that occured in the Red Sea."

 

[ScubaTexan]

someone suggested I edit out David Bloom's name. This was a major news story on all networks, as was his cause of death....so whatever ya'll think.

David Bloom's death is a matter of record and he was a public figure. Nothing wrong here. Keep it in.

 

[Scuba]

My gratitude goes to Rob and his family, and those with pertinent knowledge of this accident willing to share information. Let us try and do the best analysis possible based on the information we can obtain. This is something that, everyone willing to contribute in this manner for the possible benefit of other divers is deserving of. In the end, if we can achieve an exemplar model of the analytical process and derive a more detailed account of events, which would not only be in addition to, but also enhance any personal lessons individual divers may find, or any suggested changes in widespread practices - it would be a worthy step in the right direction, and the least we owe to Rob and family from my perspective.

Before going off into educated speculation about what could have happened here and there, lets try and fill in some of the missing or questionable chain of events and their timeline, as well as try and gather pertinent missing information. Let's solidify believed facts.

It would be greatly helpful if drmike, and anyone else with pertinent information was willing to make themselves available here to answer further enquiry, or at least to relay the info through others.

From the mentioned article on Divernet.

Sheryl, Rob's widow:

"We know he released his weightbelt and ascended very rapidly. I was told
[that] ten minutes after the divers went down, the boat crew found him floating face
down."

From first post:

He was seen by crew just under the surface unresponsive

Somewhat different accounts regarding buoyancy, maybe we can get a definitive account that would eliminate the buoyancy issue. Just to reiterate a point.

He was seen by crew just under the surface unresponsive
We send out a zodiac and dragged him on board and brought him back to boat
we tried cpr but he was gone, no pulse not breathing

Per Dr Mike's account from first post, dive time according to computer was 4 minutes. This indicates he lost consciousness or responsiveness within aprox 6 min of reaching the surface, since per buddy's account he was seen swimming at surface. How long was he observed at surface by buddy?

Any foaming visible upon recovery or other telling signs?

What was the time from spotting to checking pulse and breathing?

How far away from the boat was he spotted? Area of descent relative to boat, to where he was found? Currents? What were surface and depth conditions?

I assume, which others may be able to confirm, he had various surface signal devices. No mention of usage.

He surfaced, there is no account of any deployed or noticed signal for help, (can we verify this?) was seen swimming towards boat by buddy. I'm assuming buddy could see both he and the boat, or deduced boats location.

Probable scenario: Even if experiencing some sort of distress, he likely thought he could safely make it to the boat without inconveniencing anyone. Though at some point during the aprox. six min. surface interval he probably suffered rapid incapacitation of some type, unable to call for assistance. It's possible audible signal tool usage may have been missed, or vocal or visual arm waving.

Maybe our medical experts, or others, can rather conclusively eliminate or point towards certain medical complications if we are able to establish a more precise timeline, and symptoms upon recovery.

Regarding buddy issues, unless he is willing to share pertinent dive plan information, no blame can be conclusively placed on him. If he does share this information, it’s also possible he could conclusively, satisfactorily, be absolved of any wrongdoing, as per his account reinforced by the knowledge of those who have buddied with Rob in the past.

From what we know of buddies account its safe to say he did not notice any distress. From Rob’s bail out to ascent to swimming towards boat. Except for the actual bail out situation. Can we confirm that ascent rate was normal? Has anyone seen his dive
computer dive profile. Is this info available.?

Since I do not know about rebreathers I would encourage those who do to further enquire and comment regarding what they consider to be pertinent information. And fill in some blanks when possible relating some degree of probability.

I hope we can all work together without seriously offending anyone.

 

[caveseeker7]

Let me try this again:

Mouthpiece could not close due to miss aligned center screw.
Screws that secure both hose colars to mouthpiece missing
so could not open/close mouthpiece correctly.
Screws that secure both hose colars to mouthpiece missing
so could not open/close mouthpiece correctly.
Added:
Unit later shown to have flooded (but as he couldnt close the
mouthpiece it could have flooded during ascent after bailing)

This would explain some of the loss bouyancy the led to Rob being below the surface.
Water in the lungs also will have the same effect.

I pulled the hose collar screws on an Inspo DSV/hose connector, the DSV can be closed but it takes several attempts. The DSV is unique as it doesn't have a lever or knob that rotates the inner barrel, instead one holds the connector and turns it relative to the DSV housing. The hose collar screws tighten the hose connector to the inner barrel.

This is something that Rob should have noticed when he assembled and pre-dived his rebreather.

Mouthpiece had foreign object inserted into it (for some reason)
it reduced internal bore dia. considerably

This is, in my opinion, the most important part.

The inner diameter of the barrel was indeed considerably reduced by the foreign object, my estimate is close to 50%. That restriction was on the exhalation side IIRC. In addition the foreign object also blocked about half of the opening where the bite piece attaches. That increases WOB on both inhalation and exhalation.

Again, this is something that Rob should have noticed when he assembled and pre-dived his rebreather. This was not a small screw as the one he missed on the hose collar. It was a rather large object that fits tightly inside the inner barrel. Takes a bit of effort to get it in and out. There is no way that it could end up in there by chance. The DSV was assembled the wrong way, since the object was foreign AP cannot be blamed for it.

With increased ambient pressure the gas density increases, at 80 ft about 2 1/2 times that at the surface. So the effects of the increased WOB will increase with depth. Hence I believe that Rob retained CO2, felt the symptoms of hypercapnia and bailed out.

Between the CO2, physical stress of the surface swim and the other "cascading" factors mentioned in one of my earlier posts I really believe that there is a likely chance that he indeed suffered a heart attack. That would also explain while he didn't signal once he realized he was in trouble. Because by then he couldn't.

When he first surfaced he probably wouldn't have done it anyway, the man faced danger before. He had a problem, bailed to OC, got to the surface. Proper procedure, problem taken care of.
"Just a short swim and I'll fix that SOB ... "

So, brief version of what I believe happened:
- Foreign object obstruction due to complacency
- Hypercapnia due to obstruction
- Heart attack due to CO2 and physical stress/exhaustion
- Drowning due to heart attack

I don't believe there are any major new lessons to be learned here.
Rule number two, "complacency kills", is rather well known.

And that's about all I have to say on the subject, and certainly all I want to write about. I'll go for a walk on the beach and watch the sun set, remember a friend. Tears me up inside that the old sod got complacent, I miss him a lot. Every time I come here, or to RBW, every time I start up IM. Every time I eat at the Fill Station we used to go to. Every time I think of him.

 

[scubapolly]

So, brief version of what I believe happened:
- Foreign object obstruction due to complacency
- Hypercapnia due to obstruction
- Heart attack due to CO2 and physical stress/exhaustion
- Drowning due to heart attack

I don't believe there are any major new lessons to be learned here.
Rule number two, "complacency kills", is rather well known.

And that's about all I have to say on the subject, and certainly all I want to write about. I'll go for a walk on the beach and watch the sun set, remember a friend. Tears me up inside that the old sod got complacent, I miss him a lot. Every time I come here, or to RBW, every time I start up IM. Every time I eat at the Fill Station we used to go to. Every time I think of him.

Thanks for the info, and the touching statement.

 

[ianr33]

What was this "foreign object" ? Was it part of the rebreather or something else entirely?

 

[caveseeker7]

What was this "foreign object" ? Was it part of the rebreather or something else entirely?

A component of another piece of equipment he owned. Not part of his rebreather.

 

[ianr33]

Thanks for the reply

Any idea how it got there? Is the presumption that it fell in accidentally and was not noticed? Am just having a hard time picturing this.