Filmmaker Rob Stewart dies off Alligator Reef

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Just a reminder, too much bickering & speculation which could be read by family & friends who are crushed is not what we are at Scubaboard....
They are all in my thoughts & prayers......
 
I know nothing about CCRs, this may be a dumb question, but wouldn't that scenario require them both to have had their own independent failures? Seems unlikely, though not impossible, which is why I (like you) keep coming back to the neuro-DCS theory.

I can come up with a simple way to general simultaneous failures provided they were both following the same protocols. Since it was the third and last dive of the day it makes it more likely that they were low on scrubber and/or onboard O2 and dil. Also if it was a bounce dive "just to remove the hook" then they could have cut other corners. It could happen as simply as "its just a bounce to clear the hook, you only need to bring your dil bottle as bailout we won't be doing any deco" and then failure to swap out O2 bottles, combined with both of them running out of O2 as they flushed on the ascent since both of them started low.

Failure to swap out or charge bottles in CCR divers is not going to be that uncommon either since you don't use very much gas doing a CCR dive, and you start looking at 1500psi as more than enough to do a dive and normalization of deviance only gets worse from there.

EDIT: so one obvious problem here is that on a 220 ft / 70m dive it would be more appropriate to have 18/45 as dil/bailout which wouldn't cause hypoxic issues. Now you have to add that they were diving with 10/70 dil/bailout or something like that as well, which would be an odd choice to make. If the dive was a bit deeper, or the earlier dives had been a bit deeper this would become more plausible. So yeah, I'm still pretty skeptical about this possibility, but its still useful to think it through since there's some good lessons for CCR divers.
 
I didn't meant to give that impression and apologise if I did. I more wanted to point out that in normal operation a hypoxic dil does not in itself cause issues above 20ft as I interpreted the post by Q1988. That's not to trivialise the precautions that must be taken in any way.

-Mark
I ask because some mCCRs will not sustain a breathable po2 (especially under times of exertion) without the diver manually adding oxygen.

Distraction + Exertion = (can =, at least) hypoxia.
 
I've probably missed it within the thread, but why do some posters seem to believe he's floating?
He was in a drysuit. If he is alive, he is floating. If he has passed, a body starts to generate gas almost immediately. So he is floating.
 
He was in a drysuit. If he is alive, he is floating. If he has passed, a body starts to generate gas almost immediately. So he is floating.

Not necessarily, a body below about 100' won't generate enough gas to overcome the pressure and become buoyant.
 
I can come up with a simple way to general simultaneous failures provided they were both following the same protocols.

Or to put it another way, simultaneous independent failures are very unlikely, but real failures are rarely truly independent. Following the same protocols, exposed to the same conditions, and so on... I'll take "cascading" over "independent" any time. </tangent>
 
So that rules out DCS. Sounds like a problem with the scuba units. If the instructor did something unwise, it is not so hard to believe that the former student would follow his lead. So it could have been a problem or mistake that was common to both divers... Not two independent failures... I would think is more likely.
 

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