Filmmaker Rob Stewart dies off Alligator Reef

[John Bantin]

John,

your advice to surface and "Get off the loop" is totally contrary to any CCR training. The recommended training advice for the Rebreathers is to stay on the loop until you are securely back on the boat or on dry land. This is best practice both before the dive "pre breathing" and upon surfacing.

Always know your PO2.

 

[Dan]

Ya, on the bed PO2 = 0.21 isn't it?

 

[mderrick]

The nature of the rEvo BMCL design (or any BMCL in particular, and to a lesser extent all units) results in the following consideration....

 

[oya]

CO is scrubbed pretty quickly from the loop by the same mechanism that cleans CO2.

Uhm... What?

 

[Capt Tom McCarthy]

Fatigued, he probably accidentally flooded his loop swimming from the buoy to the boat and could not cope with the suddenly heavy rebreather. That's the simplest theory that fits the facts as I understand them.

I disagree with this. I've never been so fatigued that I just let my loop fall out of my mouth nor have I heard of this ever. Hypoxia is more likely, considering the mix used coupled with distraction and a hard surface swim.

 

[KevinNM]

CO is scrubbed pretty quickly from the loop by the same mechanism that cleans CO2. Remember, very little dil is used by a competent rebreather pilot. If it were a problem, then it would have manifested itself on the first two dives. and we know it did not. Sotis' stupor on the boat is consistent with CO2 as was his combativeness. It's my understanding that he had a problem getting up the ladder as well, but he never passed out. Again, there's no compelling reason to believe that Stewart had the same issue as Sotis. He was in much better shape and gave a clear OK signal on the surface. Fatigued, he probably accidentally flooded his loop swimming from the buoy to the boat and could not cope with the suddenly heavy rebreather. That's the simplest theory that fits the facts as I understand them.

Can you show me where the manufacturer says sofnolime absorbs carbon monoxide? I can see in the molecular products data sheet where it can produce carbon monoxide if run hot and dry, but not anything about it absorbing it..

 

[oya]

Can you show me where the manufacturer says sofnolime absorbs carbon monoxide? I can see in the molecular products data sheet where it can produce carbon monoxide if run hot and dry, but not anything about it absorbing it..

All it takes to understand this is a high-school level understanding of chemistry. It's a four step process that goes thus:

1: CO2 + H2O --> H2CO3
2: H2CO3 + 2 NaOH --> Na2CO3 + 2 H2O + Energy
3: Na2CO3 + Ca(OH)2 --> CaCO3 + 2 NaOH

4: Meanwhile, CO sees all this math and runs, screaming, from the classroom. Thereby CO is eliminated from the breathing gas.

 

[nadwidny]

All it takes to understand this is a high-school level understanding of chemistry. It's a four step process that goes thus:

1: CO2 + H2O --> H2CO3
2: H2CO3 + 2 NaOH --> Na2CO3 + 2 H2O + Energy
3: Na2CO3 + Ca(OH)2 --> CaCO3 + 2 NaOH

4: Meanwhile, CO sees all this math and runs, screaming, from the classroom. Thereby CO is eliminated from the breathing gas.

I must be CO because that pretty much describes high school for me.

 

[St John the Diver]

I disagree with this. I've never been so fatigued that I just let my loop fall out of my mouth nor have I heard of this ever. Hypoxia is more likely, considering the mix used coupled with distraction and a hard surface swim.

And the far too sensitive ADV of the rig.

There are several plausible hypothesis. And there's little likelihood of ever knowing which one actually occurred.

 

[rjack321]

CO is scrubbed pretty quickly from the loop by the same mechanism that cleans CO2.

Ummm no. Did Sortis "teach" you this on your bootleg Revo course?

It's bogus, CO is not removed or catalyzed by sorb.