Contaminated gas is a silly theory. That bites you towards the beginning of the dive, not the end, or certainly as yo start to descend and the partial pressure of the contaminant builds.
Sudden unconsciousness on a CCR sounds like hypoxia. But it is, of course, hard to say what happened without knowing any more details than "he blacked out." Two people at once is certainly bizarre.
Questions that one would want answered before even starting to frame a hypothesis:
What was their dive plan?
What was their dive time?
What was their actual profile?
Does their computer show anything unusual?
What does their computer show the PO2 as?
What rebreathers?
What breathing gasses?
How long had they each been diving that unit?
What was the state of the rebreather?
How long did they have on their scrubbers?
And on and on and on and on.
But please do go on and speculate wildly. It is fun to read.
In the meantime there's nothing wrong with hoping for a miracle, but my deepest condolences to his family, friends, and the boat crew. Godspeed to the searchers.
Sudden unconsciousness on a CCR sounds like hypoxia. But it is, of course, hard to say what happened without knowing any more details than "he blacked out." Two people at once is certainly bizarre.
Questions that one would want answered before even starting to frame a hypothesis:
What was their dive plan?
What was their dive time?
What was their actual profile?
Does their computer show anything unusual?
What does their computer show the PO2 as?
What rebreathers?
What breathing gasses?
How long had they each been diving that unit?
What was the state of the rebreather?
How long did they have on their scrubbers?
And on and on and on and on.
But please do go on and speculate wildly. It is fun to read.
In the meantime there's nothing wrong with hoping for a miracle, but my deepest condolences to his family, friends, and the boat crew. Godspeed to the searchers.