Cave diving on CC is safer than on OC?

[rjack321]

I will make this easy to understand. The general population of the US and probably the rest of the world are oblivious morons. There are many of these morons that have the money and desire for a ccr. Many of these morons you’ve probably seen at sites or dove with because they’re ubiquitous.
Once you realize most of us are stupid and that no human is infallible, the quicker you’ll (generlized you) understand why people who are taught to monitor their po2 don’t amongst other things like not checking gases

And some of them even have youtube channels!

 

[OTF]

Here's a hot take:

"Always know your PO2" is a nice mantra and convenient way to blame accident victims but given what we know of the human brain and safe operation principals from other industries it's actually not practical or sensible to bet lives on people (including the smart experienced ones) being able to perfectly watch a number with absolute consistency at all times while also trying to work underwater, enjoy a dive, or solve problems often simultaneously. Brief distractions DO happen, even to the best divers, who mostly don't admit it. It's ridiculous that PO2 alarms aren't standard.

 

[Underwater Tourist]

I will make this easy to understand. The general population of the US and probably the rest of the world are oblivious morons. There are many of these morons that have the money and desire for a ccr. Many of these morons you’ve probably seen at sites or dove with because they’re ubiquitous.

There is a bright side though.

We have less and less cave and ccr fatalities compared to 10-20 years ago, so the proportion of morons is decreasing. I am sure there is a natural lower limit that we cannot cross, but we probably haven't reached it yet, meaning there is more room for progress!

Natural selection helps as well

 

[PfcAJ]

Why don't people notice their PPO2? That's the #1 mantra for diving a rebreather: Always know your PPO2

On OC, you always need to do a NoTox drill when switching regulators on OC. Plenty of failures with that as well as mis-analysing or mis-labelling gas.

At least on a box you ride it to the surface, continually adjusting the PPO2 as you go, no gas switching required.



Which is a training issue? Definitely an experience issue.

Arguably it's an issue when diving a full electronic CCR as you get more complacent that the computer will sort things out: if something's virtually always OK, you don't notice when it isn't. One hopes that people diving manual or hybrid rebreathers would be very aware of their PPO2.

Mantras are nice but reality is that people don’t always monitor the po2. Ffs, there was a fatality a few years ago where the instructor blindfolded the student and, if I recall correctly, shut off their oxygen.

That isn’t even remotely an option on OC.

There was another fatality where the o2 got shut off during the dive.

These things are not possible on open circuit. Mantra or not, it happens. The fact that it even CAN happen is what makes rebreathers more dangerous. There are failure modes that impact you physiologically that don’t exist with Oc.

 

[Vicko]

Why don't people notice their PPO2? That's the #1 mantra for diving a rebreather: Always know your PPO2

Whenever I dive with a lot of reb divers at the same time I see something happen at the shallow stop. These groups are sometimes in the 10+ divers at the time.
One person will do a o2 flush, which will cause a cascade of divers finally checking their po2 and do a o2 flush too.
15 divers with the same dive profile and gradient factors and sometimes their deco times differ by 10-15 minutes because most divers I see don't actually keep track of their ppO2.

 

[PEDiver]

15 divers with the same dive profile and gradient factors and sometimes their deco times differ by 10-15 minutes because most divers I see don't actually keep track of their ppO2.

Wow, that's really concerning.

Really helps to prove @rddvets point...

 

[ofg-1]

The general population of the US and probably the rest of the world are oblivious morons.

I'm an idiot dammit, not a moron! Just try to make something idiot-proof, and we will build a better idiot.

 

[rddvet]

so the proportion of morons is decreasing.

You must be a shut-in. I see more and more morons in everyday life.

Blink twice if you need to be rescued from your captor

 

[Marie13]

You must be a shut-in. I see more and more morons in everyday life.

Blink twice if you need to be rescued from your captor

I call it the “epidemic of stupidity.” It’s very widespread.

 

[Wibble]

Whenever I dive with a lot of reb divers at the same time I see something happen at the shallow stop. These groups are sometimes in the 10+ divers at the time.
One person will do a o2 flush, which will cause a cascade of divers finally checking their po2 and do a o2 flush too.
15 divers with the same dive profile and gradient factors and sometimes their deco times differ by 10-15 minutes because most divers I see don't actually keep track of their ppO2.

As an aside, last weekend I was on a boat where a diver had to cancel his dive (due to some family emergency) before we got on and was picking up his kit he'd left on the boat from the previous two days of diving.

He is completely blind.

He was diving an AP Inspiration rebreather (as it has a buzzer).

I'm completely amazed. He's well known and has a good reputation for diving wrecks.