Rob Stewart and Third Dive

[Kay Dee]

Rob's shearwater profile doesn't support hypoxia at all.

Acute (cerebral/ type 2) DCI is really the only plausible explanation and it affected both of them in the first few minutes after surfacing. The "deco stop" was so short it may not have been acute nor even had any type 1 symptoms at that time/yet. Peter regained consciousness on the deck, Rob was waiting behind the boat ladder, sank and drowned.

I havent really followed this closely so a question: Did Sotis develop other symptoms associated with Type2 and was he chamber treated after this event?

If so I would tend to agree with your assumption of Type2.

If not then it clearly looks to me like Sotis passing out was from hypoxia (as @bubblemonkey2 is suggesting) and then coming around after breathing a richer gas, as you dont shake off Type2 with fresh air / a bit of surface o2 after all (or that is my personal experience after a Type2 hit).

And if hypoxia was the case then it would fit Stewart also passing out (in water), droping mouthpiece (hence flooding his ccr and turning it into a 'lead' weight), drowning and sinking.

But as I said, I havent followed this closely - or maybe paid enough attention - nor read the whole thread so..............this may have all been covered / before. If so, beg pardon.

 

[hroark2112]

I havent really followed this closely so a question: Did Sotis develop other symptoms associated with Type2 and was he chamber treated after this event?

If so I would tend to agree with your assumption of Type2.

If not then it clearly looks to me like Sotis passing out was from hypoxia (as @bubblemonkey2 is suggesting) and then coming around after breathing a richer gas, as you dont shake off Type2 with fresh air / a bit of surface o2 after all (or that is my personal experience after a Type2 hit).

And if hypoxia was the case then it would fit Stewart also passing out (in water), droping mouthpiece (hence flooding his ccr and turning it into a 'lead' weight), drowning and sinking.

But as I said, I havent followed this closely - or maybe paid enough attention - nor read the whole thread so..............this may have all been covered / before. If so, beg pardon.

No, he wasn’t treated in the chamber. He was recovered deceased 2 days later 250’ below the surface on the ocean floor.

 

[J-Vo]

If the cause of injury were acute DCI due to an ascent from bottom that was too fast, how does this explain the apparently controlled deco stop in the dive profile?

I can say from experience, that on dives at this depth you can be symptom free until the last 10' ascent to the surface.

 

[Kay Dee]

No, he wasn’t treated in the chamber. He was recovered deceased 2 days later 250’ below the surface on the ocean floor.

No he wasn't, that much I know. Your talking about Stewart, while I was asking about Sotis. So if you read my post again the questions was, exactly "Did Sotis develop other symptoms associated with Type2 and was he chamber treated after this event?"

 

[Kay Dee]

I can say from experience, that on dives at this depth you can be symptom free until the last 10' ascent to the surface.

Me to, unfortunately, so to speak. And as we know you can be symptom free until you literally step off the dive ladder back onto the boat (watched that happen to others a couple of times), or say be symptom free in cave country until you walked back to your car (personal experience, again ). I treated one of the "back onto the boat" guys Type2 with IWR (using my own 'remote location friendly' IWR kit that had all the bells and whistles, i.e. coms, FFM, surface supplied gas switches, harness and 'seat', etc.) for a positive outcome; and another that was treated in an onboard chamber. S**t happens, just gotta be ready to deal with it. And the first step in that process is admitting to yourself that you are bent!

 

[hroark2112]

No he wasn't, that much I know. Your talking about Stewart, while I was asking about Sotis. So if you read my post again the questions was, exactly "Did Sotis develop other symptoms associated with Type2 and was he chamber treated after this event?"

My apologies. Someone woke me up too early on a Saturday.

 

[Kay Dee]

My apologies. Someone woke me up too early on a Saturday.

No worries.

And yeah, the results of that even gets me late in the day sometimes (and on any day, not just Saturdays either).

 

[Subfiend]

I'm talking about the possibility of accidental hypoxic diluent addition after reaching the surface. Unlikely? But possible.

Nothing to do with the dive profile, which (as posted above) does not include data on the surface, or afterwards. Was the unit/computer switched off upon surfacing?

Why didn't the computer record a fourth "dive" upon resubmersion? Or did it?

Mouthpiece out?
No gag strap or BOV?
What was the CMF config?

Clear & obvious lessons here about the consequences of underestimating DCI risk in aggressive repetitive trimix deco diving.

But still giving a think about additional possible factors/fixes. As there are additional risks on CCRs beyond just DCI

Here is the data from the surface interval, which I posted earlier. It shows the ppO2 never dropped below 0.60. Stewart made two manual additions of O2 in the first minute, then took the mouthpiece out of his mouth (the data is consistent with witness testimony), closed the loop, and thereafter the rebreather's constant mass flow device continues to add a small amount of O2 periodically for the next two minutes and the ppO2 climbs gradually. While on the surface, Stewart was breathing either a high percentage of oxygen on the CCR or air, never hypoxic diluent.

The dive computer recorded the fourth dive (see attached).

Additional factors include hypotension, fatigue, the impact of rapid ascent, the impact of a prescription medicine whose side effects include fainting and low blood pressure, etc.

 

[Subfiend]

Rob's shearwater profile doesn't support hypoxia at all.

Acute (cerebral/ type 2) DCI is really the only plausible explanation and it affected both of them in the first few minutes after surfacing. The "deco stop" was so short it may not have been acute nor even had any type 1 symptoms at that time/yet. Peter regained consciousness on the deck, Rob was waiting behind the boat ladder, sank and drowned.

According to witness testimony and statements, Sotis never lost consciousness. Instead, he climbed onto the boat with the CCR mouthpiece in his mouth, removed it and then, within 30 seconds, he was in a zombie-like state, mumbling incoherently and unable to move. His wife and the mate sat him down, tried to administer oxygen using his CCR and, when this was unsuccessful, they administered oxygen from the boat's O2 kit.

 

[Subfiend]

And if hypoxia was the case then it would fit Stewart also passing out (in water), droping mouthpiece (hence flooding his ccr and turning it into a 'lead' weight), drowning and sinking.

But as I said, I havent followed this closely - or maybe paid enough attention - nor read the whole thread so..............this may have all been covered / before. If so, beg pardon.

Sotis was not treated in the chamber.
Stewart's rebreather did not flood.
The hose from Stewart's BCD to his rebreather was not connected.