Two divers critical - Hawaii

[dmaziuk]

I know I make mistakse all the time, people who claim not to worry me.

Was that deliberate? -- just curious

 

[Superlyte27]

Was that deliberate? -- just curious

It’s funny either way.

 

[dmaziuk]

It’s funny either way.

where I work it's "computers make very fast very accurate misteaks", that's the spelling I'd've gone with myself

 

[KenGordon]

In these days of autowreck what do you th8nk?

The only accidental mistakes are logic, capitalisation and when the iPad inserts numbers instead of letters, I’d be eternally grateful if anyone knows how to switch 5hat off.

 

[fsardone]

Dude, that’s awesome. I’m adding it to my signature.

.... thanks! the wording might be mine but the concept is so old I do not remember where and when I picked it up.

Cheers

 

[pepperbelly]

I was just brainstorming.
I have never used a CCR so I don’t have an informed opinion.
I have been diving since the early ‘70s- with a J-valve, no octo, no spg, no bcd. I like those now by the way.
My point is that things evolve and change over time. With SCUBA and CCR those changes are, and should be slow, but changes are usually for the better.

 

[fsardone]

I was just brainstorming.
I have never used a CCR so I don’t have an informed opinion.
I have been diving since the early ‘70s- with a J-valve, no octo, no spg, no bcd. I like those now by the way.
My point is that things evolve and change over time. With SCUBA and CCR those changes are, and should be slow, but changes are usually for the better.

Hello Pepperbelly,
sorry if my reply appeared harsh or abrasive ...
Fact is that scubadiving brings you in an hostile environment: it cannot sustain life. You are totally reliant on your life support equipment. Therefore you need to understand it, use it within limitation and do not uderestimate its failure modes. Tjis is true for OC and CCR.

In addition while OC failures will be immediately apparent (freeflow, no gas and gas leaks). CCR failures will sneak on you because you might be able to keep breathing unimpeded but a non life sustaining gas (hipoxic like in this case, hiperoxic or CO2 laden).

The change, as you say it, is what you CHOOSE to dive and how much experience you have. Zero to Hero kills, especially if you task load yourself. I have been diving since 1980 with J-valve and no BCD, when I showed up with an SPG on my reg, my father told me was not necessary the "valve" was going to tell me when gas was low ...

I was hipoxic trimix cert before starting CCR in 2014. I am still just normoxic trimix cert on CCR because I believe I need a bit more experience in CCR before going (much) below 60 meters and start playing with 10/60 in my dil ... while there are people mixing their own heliair (10/50), without even a pale understanding of what an automatic dil valve firing on surface might do to them (put them to sleep with probable no wake up: solenoid and oxygen MAV especially on the expiration side will be too slow). But they class themselves expert.

It is the Dunning–Kruger effect - Wikipedia. Doing things complex and difficult requires studying training and experience. Above all humility to approach the field with the "need to learn" approach. Diving is not for everybody. Even more so CCR diving.

Cheers

 

[John the Pom]

Exactly.

The pre-flight check is important in OC or CCR. And in both cases, it should be done AFTER you have donned the unit, just before you enter the water, as I mentioned upthread. All the various build checks don't replace that.

For OC it's simpler but still important. When I dive OC, after I'm in the unit, ready to splash, I fill my wing, and take three breaths off each regulator while looking at the SPG. If the valve is off or nearly off, you can still draw a breath on the surface, so watching the SPG is important.

If divers are ignoring essential pre-dive safety checks, it points to a bad safety culture amongst some people. I think a lot of divers would agree that relatively shallow open-water O/C scuba diving does have a poor safety culture - you meet plenty of people who probably shouldn't be diving, but they do, and mostly get away with it. It is a problem though if they take that attitude into e.g. deep O/C diving, overhead environments, or (I guess) CCR diving.

Surely it would be obvious to a buddy / instructor if someone hasn't performed a pre-dive breathing check with their CCR, if it involves breathing on the loop for several minutes? People need to call that out as unacceptable. A good safety culture means that everyone is committed to safety, not just paying lip service to it. Instructors / senior people with a poor attitude to safety can have a very damaging effect on the safety culture because they can pass-on bad habits to less experienced divers who don't know any better: "It says in the book to do this, but real divers never bother with it...". You need some sort of supervisory framework with real teeth to eradicate that.

 

[KenGordon]

If divers are ignoring essential pre-dive safety checks, it points to a bad safety culture amongst some people. I think a lot of divers would agree that relatively shallow open-water O/C scuba diving does have a poor safety culture - you meet plenty of people who probably shouldn't be diving, but they do, and mostly get away with it. It is a problem though if they take that attitude into e.g. deep O/C diving, overhead environments, or (I guess) CCR diving.

Surely it would be obvious to a buddy / instructor if someone hasn't performed a pre-dive breathing check with their CCR, if it involves breathing on the loop for several minutes? People need to call that out as unacceptable. A good safety culture means that everyone is committed to safety, not just paying lip service to it. Instructors / senior people with a poor attitude to safety can have a very damaging effect on the safety culture because they can pass-on bad habits to less experienced divers who don't know any better: "It says in the book to do this, but real divers never bother with it...". You need some sort of supervisory framework with real teeth to eradicate that.

Prebreathing is supposed to check the scrubber, but it turns out most people can not detect an broken scrubber in the prebreath time. I prebreath my unit to check that it holds a setpoint. Mostly this checks that the thing is on, at the appropriate setpoint and that the solenoid is working. The first two I know from the handset so I am only really testing the solenoid. I don’t necessarily do this immediately before jumping in, but in the general run up. It doesn’t take a long time. So when might some ‘supervisory framework’ notice?

Just like cleverer, foolproof rebreathers are not the answer, some external authority is not the answer.

So far every CCR diver I have met, in the flesh, seems to exhibit good practice. Having said that, all the fatalities (maybe there are exceptions but none come to mind) involve divers failing to follow proper practices - ignoring direct medical issues precipitated by diving.

The answer is proper training and attitude. This comes from instruction and education instilling proper behaviour, understanding the potential concequences and understanding that people make mistakes so double checking is required.

 

[pepperbelly]

Hello Pepperbelly,
sorry if my reply appeared harsh or abrasive ...
Fact is that scubadiving brings you in an hostile environment: it cannot sustain life. You are totally reliant on your life support equipment. Therefore you need to understand it, use it within limitation and do not uderestimate its failure modes. Tjis is true for OC and CCR.

In addition while OC failures will be immediately apparent (freeflow, no gas and gas leaks). CCR failures will sneak on you because you might be able to keep breathing unimpeded but a non life sustaining gas (hipoxic like in this case, hiperoxic or CO2 laden).

The change, as you say it, is what you CHOOSE to dive and how much experience you have. Zero to Hero kills, especially if you task load yourself. I have been diving since 1980 with J-valve and no BCD, when I showed up with an SPG on my reg, my father told me was not necessary the "valve" was going to tell me when gas was low ...

I was hipoxic trimix cert before starting CCR in 2014. I am still just normoxic trimix cert on CCR because I believe I need a bit more experience in CCR before going (much) below 60 meters and start playing with 10/60 in my dil ... while there are people mixing their own heliair (10/50), without even a pale understanding of what an automatic dil valve firing on surface might do to them (put them to sleep with probable no wake up: solenoid and oxygen MAV especially on the expiration side will be too slow). But they class themselves expert.

It is the Dunning–Kruger effect - Wikipedia. Doing things complex and difficult requires studying training and experience. Above all humility to approach the field with the "need to learn" approach. Diving is not for everybody. Even more so CCR diving.

Cheers

No worries. Your reply wasn’t harsh.
From reading posts by CCR divers talking about details like normoxic gas mixes etc. I can see where having fewer automatic adjustments may be safer.