Regular quarry diver found dead - Falling Rock Park, Kentucky

[rjack321]

Not really. My father used to dive O2 rebreather to 20 mt (60+ ft) it was 1950s many things were unknown but the trick was not flushing well to keep the PO2 low. Due to the way the O2 CCR works, it only add gas when the volume goes to below a normal breath (is a demand valve like a second stage) so there is achance to metabolize most of the oxygen but still have enough Nitrogen not to trigger the valve, guess that is what you meant by pump it full of ambient air.
Fact is when you are deep (not below 6 mt ) you might have enough oxygen to keep you awake but raising up just few meters or using up the 21% you have in the bag if you did not flush will leave you unconscious.

Not sure you have a training course for a self built ... and you might not have all the details if you are a self tought pure O2 CCR diver.

What I meant was if you start with an empty CL you wont be able to make it hypoxic. You don't have to flush even, just inhale until the CL bottoms out, exhale through your nose and then refill the CL with O2. I guess that's a flush but not really.
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I didn’t even know that homemade rebreather were a thing. I am not sure I’d trust myself enough to make one ...

Most homebuilders are fairly studious. And certified on other units in addition to whatever they create on their own.
Rebreathers are pretty simple and actually were in use before open circuit scuba was developed. They don't have to be "high tech" to work.

 

[doctormike]

Very sad event. I have dived may times at FRP although don't dive there often.

My reading of the media report above in says that the victim built a "home brew rebreather" but doesn't indicate that is what he was diving at the time of the incident.

That's true. It does make for interesting discussion, but we don't actually know if he was diving OC or another rebreather at the time os his death.

I associate "shallow water hypoxia" with breath-hold or free diving in which divers hyperventilate "blowing off" enough Co2 to allow them to resist the urge to breathe to the point of passing out after having metabolized the available oxygen. These divers usually pass out during the ascent near the surface when the PPO2 is dropping - hence the "shallow water" moniker..

Terminology issue - I agree. "Shallow water hypoxia" is generally used to refer to free divers. I guess we need another term for hypoxia that happens in shallow water (or on the surface) to rebreather divers.

If Mr. Price were diving a rebreather it seems to me that this accident may be attributable to hypoxia due to failure of o2 sensor(s). Can't say how many (if any) redundant O2 sensors were in place in a "homebrew" rebreather.

Possible but less likely. I think that sensors failing as current limited (putting you at risk for hyperoxia) is more common than a significant overreading of PO2. On the other hand, there are a number of examples of the sensors working just find, but the diver not paying attention to them. Doesn’t matter how many cells you have if that’s the problem.

If his "homebrew rebreather" was an oxygen rebreather, he could have suffered oxygen toxicity due to diving to unsafe depths (even 40' on pure O2 is a PPO2 of over 2ATA and would be unsafe). Hypoxia seems less likely a scenario as an O2 rebreather uses only O2 in the loop and therefore consuming the o2 in the loop would reduce the volume in the loop which I would expect to alert the diver to a problem before becoming hypoxic.

Was there some information that he was diving an O2 rebreather? I didn't see that, but it has been brought up a few times. I'm sure that there are people out there who dive them recreationally, but I don't think that is very common - I dive with a lot of rebreather divers and I have never seen one. Not saying that they don't exist, but my understanding was that they were primarily used for covert operations.

Since he was found on the bottom at 19 feet, the only way that hyperoxia could have been involved would be if he toxed at a deeper depth, and then something caused his body to move up the slope of the bottom without ascending to the surface. A fairly unlikely scenario.

 

[rjack321]

Terminology issue - I agree. "Shallow water hypoxia" is generally used to refer to free divers. I guess we need another term for hypoxia that happens in shallow water (or on the surface) to rebreather divers.

Hypoxia is hypoxia. We don't need new terms for a lack of oxygen leading to unconsciousness.

Was there some information that he was diving an O2 rebreather? I didn't see that, but it has been brought up a few times. I'm sure that there are people out there who dive them recreationally, but I don't think that is very common - I dive with a lot of rebreather divers and I have never seen one. Not saying that they don't exist, but my understanding was that they were primarily used for covert operations.

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"Metzmeier told WDRB Price was "very experienced," having built his own oxygen system for breathing while diving called a "re-breather."
Can't tell if it's a mixed gas or an oxygen rebreather from this at all.

Homebuilt rebreathers are often oxygen rebreathers because you don't need any ppO2 monitoring with them. So they are simple and electronics free. Or even if they do have monitoring it's simple and one cell (like the drager O2 monitor used in their semiclosed units)

O2 RBs are also somewhat commonly used for decompression. So they are not just a military thing.

 

[Jerrod]

Is this Dale’s friend Dennis? I have to assume it is. Those are the only two people I have seen make rebreathers. Does anyone know if he was black and bald on top?

 

[DandyDon]

Is this Dale’s friend Dennis? I have to assume it is. Those are the only two people I have seen make rebreathers. Does anyone know if he was black and bald on top?

It appears so from a FB page for the same name and city: Dennis Price

 

[happy-diver]

I didn’t even know that homemade rebreather were a thing. I am not sure I’d trust myself enough to make one ...

There's a homebuilt rebreather in post 6
come on, I'm falling flat on my face here

It's called the B.U.M. Breathing Underwater Machine

 

[BlueTrin]

There's a homebuilt rebreather in post 6
come on, I'm falling flat on my face here

It's called the B.U.M. Breathing Underwater Machine

It may come as a surprise to you that I didn’t read this thread before the time I made that post ?

Maybe a big surprise but not worth falling on your face

Also your picture is really cool, looks too polished for homemade, need to add some sellotape

 

[clownfishsydney]

I didn’t even know that homemade rebreather were a thing. I am not sure I’d trust myself enough to make one ...

Back in the mid-1990s there were a lot of divers in Sydney making their own rebreathers. They used these for a quite a while till commercial rebreathers became available.

 

[W W Meixner]

It seems he entered the water with a buddy, then they separated, and I guess that buddy never checked on him even after the dive. I had buddies leave the NM Blue Hole without telling me a couple of times. The first time I quickly searched the hole on my pony; the second time I climbed the stairs and looked first, seeing him at the pickup.

Oldham County Police identify Louisville man who died in apparent drowning at Falling Rock Park quarry

Don...

Have you kept a 2019 international fatality total...this years number has to be horrendously high...and totally out of the annual norm...

It also seems to be more related to seasoned divers than it is to newbies...

There is a project here for any interested party with the time...I'd certainly be curious to see if there are any defined root causes...that show a trend...

Best...

Warren

 

[DandyDon]

Don...

Have you kept a 2019 international fatality total...this years number has to be horrendously high...and totally out of the annual norm...

It also seems to be more related to seasoned divers than it is to newbies...

There is a project here for any interested party with the time...I'd certainly be curious to see if there are any defined root causes...that show a trend...

Best...

Warren

DAN publishes annual reports with as much information as available.