Waterford Garda dead - County Wexford, Ireland

[KenGordon]

If a pilot fails to notice a low engine oil pressure indication and loses an engine/crashes as a result, the accident investigation board will find that the causal factors were mechanical failure exacerbated by human error.

Fact is, we know he had the high PO2 alarm because it registered on the handset. So the information was there. You also don't tox instantly. It's not unheard of for people to swim around at double the max safe limit for quite awhile before toxing. It's not instantaneous. The reality is, he likely had time to recognize what was happening and failed to react for some unknown reason. There's no other conclusion to draw without more info. The unit failed in a way that the diver should have recognized and been able to correct. Mechanical failure exacerbated by human error. It's easy to blame the machine, but that hides training and proficiency deficiencies in a lot of cases.

If a diver failed to respond to a free-flowing first stage and ran out of gas, we would rightfully blame the diver in most cases. Because the expectation is that gear will eventually fail and it's the diver's responsibility to respond appropriately to a logical extent. There's nothing here that indicates to me this was outside of what a trained rebreather diver should be able to manage. Maybe it was, but there's no reason to think that, given what's known.

Bugger, I should have read your post before making mine!

 

[Jack Hammer]

If someone dies because they have a freeflow on a twinset but fail to shutdown do you blame the regulator?

I dont believe Deep Life sells regulators.

 

[Celt]

If a diver failed to respond to a free-flowing first stage and ran out of gas, we would rightfully blame the diver in most cases. Because the expectation is that gear will eventually fail and it's the diver's responsibility to respond appropriately to a logical extent. There's nothing here that indicates to me this was outside of what a trained rebreather diver should be able to manage. Maybe it was, but there's no reason to think that, given what's known.

A silly comparison, a diver has time to respond to a free flow, convulsions could be instant at 70meters with a toxic gas. That’s the reason the bailout is OC it’s dependable. How a manufacturer can blame a user when their equipment fails with the excuse that they failed to switch to an alternative system is mind boggling. Maybe they should start publishing the amount of times people do manage to bailout, that would make interesting reading

 

[helodriver87]

A major free-flow at depth could absolutely kill you quickly if you failed to react appropriately. Especially in an overhead (which I'm aware isn't relevant to this accident). You might quickly end up without enough gas to exit.

It's not instantaneous. As has been mentioned twice now. Runaway O2 injection is very apparent. You feel it in your buoyancy and breathing effort. You see the cell readings start to climb. And even north of 2.0, you're not going to insta tox from a couple breaths. There's time. You see high PO2, you don't breathe it. Shut down the O2 if necessary and get off the loop. It can be done very quickly.

Bailout is a critical component of any rebreather system. So yes, it's completely reasonable to blame a trained diver for failing to bailout in a clear bailout scenario. Again, equipment will fail. That's a given on OC or CCR. You seem intent on putting all the blame on CCR manufacturers and absolving the diver of any responsibility to know how to manage failures.

 

[KenGordon]

A silly comparison, a diver has time to respond to a free flow, convulsions could be instant at 70meters with a toxic gas. That’s the reason the bailout is OC it’s dependable. How a manufacturer can blame a user when their equipment fails with the excuse that they failed to switch to an alternative system is mind boggling. Maybe they should start publishing the amount of times people do manage to bailout, that would make interesting reading

Tox is not at all instant. There are loads of examples of people taking 10s of minutes to tox. ppO2 of 3 or 4 even takes a while. The examples I am thinking of were two deaths a year apart presented by Martin Parker at Eurotech, due to similar DIY jobs on his CCRs, and a cave diver who assumed is cylinder of air was air and didn’t test it when it was actually 100%

Honestly a tox takes longer that losing all the gas out of a twinset. CCR’s main win is time.

 

[uwxplorer]

A silly comparison, a diver has time to respond to a free flow, convulsions could be instant at 70meters with a toxic gas. That’s the reason the bailout is OC it’s dependable. How a manufacturer can blame a user when their equipment fails with the excuse that they failed to switch to an alternative system is mind boggling. Maybe they should start publishing the amount of times people do manage to bailout, that would make interesting reading

Not sure what you are trying to get at... A few of us have provided rationale/cases for when a perfectly functional unit leads to the death of diver by oxtox because of user error. A perfectly functional unit cannot prevent the pO2 to rise unsafely at depth if the diluent is exhausted, shut off and not external diluent is actively plumbed in by the diver. This is not saying that this what happened in this particular case, or claiming that there wasn't a problem with the unit.
The point is that unlike driving a car, diving a rebreather can't be done safely unless the diver is on top of things. And unfortunately, a medical event, moment of distraction, unforeseen problem, can put the diver out of the parameter range in which a rebreather is safe. OC diving has similar limitations, BTW, and in some sense worse, as you could may well breath the wrong mix at depth and never been warned that your pO2 is dangerously high, since there is no HUD in an OC system...
So no, a rebreather is not a life saving device, but yes, it can be dived safely if dived properly and within well defined limits.
Deeplife's contention of having achieved the perfect rebreather that will bring you back from any and all dives can only be defended because so few (if any) divers are diving them. Just let the law of large numbers run its course and you will see the same pattern as for other units.
Eliminate the diver (think ROV) and you might get closer to a perfectly safe diving machine.

 

[KenGordon]

I dont believe Deep Life sells regulators.

If they did they’d be blaming every Scubapro OOG on how hard a Halcyon isolator is to turn.

 

[Celt]

It's not instantaneous. As has been mentioned twice now. Runaway O2 injection is very apparent. You feel it in your buoyancy and breathing effort. You see the cell readings start to climb. And even north of 2.0, you're not going to insta tox from a couple breaths. There's time. You see high PO2, you don't breathe it. Shut down the O2 if necessary and get off the loop. It can be done very quickly.

He was found on his back, unconscious after convulsing, suicide was it?

 

[Celt]

A few of us have provided rationale/cases for when a perfectly functional unit leads to the death of diver by oxtox because of user error

Rubbish, it isn’t user error if the equipment malfunctions.

 

[helodriver87]

He was found on his back, unconscious after convulsing, suicide was it?

What part of not instantaneous isn't getting through here?

I feel like we're either all failing to communicate remotely effectively or you're being difficult intentionally. It's possible to spike your PO2 to toxic levels on a perfectly functioning unit, it's possible to react to high PO2 underwater and resolve the issue, toxing doesn't happen the second you go above 1.6 and often takes some time to occur. What are you not understanding? Or are you just being disingenuous on purpose?