Scuba diving question

SixPapaCharlie

SixPapaCharlie

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So I'm following the story about the young men in Thailand that are stranded in the cave.

I read where one of The Rescuers died because he ran out of oxygen while he was under water.

How does that take place? Meaning if you are under water and the tank runs out of oxygen is it like a hypoxia chamber where you can still inhale and exhale gas but there's no O2 in it and you slowly pass away or does it mean you can no longer draw from the tank and you are painfully suffocating as you cannot take inhale?
 
Scuba tanks have compressed air, not oxygen. If it's empty you don't get any air when you inhale..
 
When a scuba tank runs dry, you can't suck out of it at all. Sometimes as you ascend the pressure differential shifts and you can get one more breath out of a tank that had been "bone dry" deeper. Scuba divers don't run on "oxygen" tanks like pilots do. At normal depths they breath straight air. At other depths the breathe various mixes that allow them to avoid some of the issues with air (high nitrogen partial pressures). Even then they substitute in fairly inert but less troublesome gases like helium rather than running on 100% oxygen which also is problematic at those pressures). Helium is not without problems as well, so they often use mixtures of all three.

But that's not what happened. It was not that he ran out of "oxygen". I don't know if they're fully understanding what happened to him, but it's not the case that he ran out of air. The places the OXYGEN is failing (and what this diver was doing) was in the chamber the kids are in. He was bringing in O2 tanks.
 
I don't know anything about what happened other than what's in this thread, but if he was diving with a rebreather, he very well could have run out of oxygen. In which case he would have gone hypoxic.
 
I’m sure I missed it, but why was a whole soccer team in a cave in the first place?
 
I had forgotten about rebreathers. Rebreathers have their own slew of problems that can go wrong. Still, I'd take anything in the press with a grain of salt. They don't much get things about diving correct anymore than they get things about aviation right.

Poking around on the Scuba counterpart to this forum, it looks like nobody there seems to have the straight poop on what happened to this diver (and equal disdains for the press reporting). Reading through it they note most of the photos show conventional tanks (air or Nitrox). There also is mention of the divers pushing things, so it's quite possible that he had DCS or just some overexhuastion rather than running out of air or experiencing hypoxia.
 
Hopefully after an investigation,the facts will come out,on the equipment involved. May he Rest In Peace.
 
I believe the diver suffocated because he estimated his air requirements based on his time in the SEALs. On his last dive, he was using more air than he thought he would. Much like flying into a headwind and not correcting your destination calculations.

One thing to note, these divers are making an 11 hour round trip doing reverse breathing. I think back to my time in 2ndForceRecon and I cannot think of a time when I would even try such a feat. These guys are supermen.
 
It's unfortunate this guy died, any dive is supposed to be done with a buddy, so if one gets in trouble the buddy can help out. I'm sure these guys work the same way. Hopefully we'll get to see a report on what happened and learn from it. This guy, along with the rest of these guys working on this are heroes.
 
cgrab said:
One thing to note, these divers are making an 11 hour round trip doing reverse breathing. I think back to my time in 2ndForceRecon and I cannot think of a time when I would even try such a feat. These guys are supermen.
Click to expand...

First, what is reverse breathing?

Second, some of the stories in the press indicate that most of the trek into and out of the cave is walkable. I'm sure some diving is necessary, but find it hard to understand how an experienced diver runs himself out of air.
 
cgrab said:
I believe the diver suffocated because he estimated his air requirements based on his time in the SEALs. On his last dive, he was using more air than he thought he would. Much like flying into a headwind and not correcting your destination calculations.

One thing to note, these divers are making an 11 hour round trip doing reverse breathing. I think back to my time in 2ndForceRecon and I cannot think of a time when I would even try such a feat. These guys are supermen.
Click to expand...
It might be an 11 hour round trip, but only a small part of that is under water. The rest of it is hiking a couple of miles carrying their scuba gear. I think I heard they are staging breathing gear along the way so the kids don't have to carry all that gear. They will walk, then don some gear to swim a stretch, then get out and walk some more and then pick up more gear to swim the next submerged section.
 
He was a retired SEAL probably not in the same shape. And stress will up your air intake. When the air is empty in a cave that's it, unless you can buddy breath. And you both don't run out.
 
Here's the cave entrance:
636662316136317962-GTY-985772232.jpg
 
I understand that the kids were in the cave as part of some soccer team initiation. I believe I read that on a news website somewhere.

It is unfortunate that one diver died in the attempt to help the children. All I read was that he ran out of oxygen, passed out and died. I don’t know if he was using normal scuba equipment or some sort of mask/helmet. But I hope he can RIP knowing he helped create a solution to save the children.
 
kyleb said:
First, what is reverse breathing?
Click to expand...

Normally you breath in and the weight of your body and the relaxed state of your muscles exhales the CO2. In SCUBA, the air is under pressure and fills your lungs then you have to force the CO2 out. You have to train your body to do it but it is still very taxing.
 
This is what it looks like to cave dive. It is seriously no joke, the slightest error or equiptment malfunction and you have little options, even with a buddy feet away from you. Now, try and drag someone who has never dove and can't even swim through this? I hope is all works out, but if someone panics while diving, they are probably going to die.
 
ejensen said:
Here's the cave entrance:
636662316136317962-GTY-985772232.jpg
Click to expand...

It says July, they went into the cave in June. Weather does not, as we all know, follow the calendar.

RIP, Seal.

I am happy it looks like that the kids may making it out.
 
cgrab said:
Normally you breath in and the weight of your body and the relaxed state of your muscles exhales the CO2. In SCUBA, the air is under pressure and fills your lungs then you have to force the CO2 out. You have to train your body to do it but it is still very taxing.
Click to expand...
A scuba regulator delivers air at the same pressure as the surrounding water, otherwise you wouldn't be able to breathe. You inhale and exhale the same as above water.
 
Interestingly, I learned to scuba dive in Thailand too. Of course I learned in a pool and already knew how to swim, and my first dive was in crystal clear water that was only 6 meters deep.

I suppose this is like a resort dive, where the dive master takes care of your boyancy and you just blob along like a manatee?

I wonder if they considered giving the kids some sort of anti-anxiety meds for the dive portion. I can't imagine how bad it would be for the rescuers if one of the kids starts panicking.
 
kyleb said:
First, what is reverse breathing?

Second, some of the stories in the press indicate that most of the trek into and out of the cave is walkable. I'm sure some diving is necessary, but find it hard to understand how an experienced diver runs himself out of air.
Click to expand...

I find it hard to understand how experienced pilots fly themselves into terrain too.

I can't imagine being underground and underwater at the same time being all that much fun. Especially in the narrow passages that might interconnect the "walkable" sections, where there is no ability to surface if needed.
 
PaulS said:
It's unfortunate this guy died, any dive is supposed to be done with a buddy, so if one gets in trouble the buddy can help out. I'm sure these guys work the same way. Hopefully we'll get to see a report on what happened and learn from it. This guy, along with the rest of these guys working on this are heroes.
Click to expand...
The story said his dive partner tried to revive him.
 
Lindberg said:
A scuba regulator delivers air at the same pressure as the surrounding water, otherwise you wouldn't be able to breathe. You inhale and exhale the same as above water.
Click to expand...
Actually you have to make a slight negative pressure to inspire to make the regulator flow (short of pushing the purge button). You don't breath out against the regulator pressure.
 
G-force said:
This is what it looks like to cave dive. It is seriously no joke, the slightest error or equiptment malfunction and you have little options, even with a buddy feet away from you. Now, try and drag someone who has never dove and can't even swim through this? I hope is all works out, but if someone panics while diving, they are probably going to die.
Click to expand...

That is seriously the most insane thing ever. Gives
me the heebie jeebies just watching that.

The top comment made me lol.

Hahaha just read the comment section it’s hilarious

85C21545-293F-408F-BAB4-C8C233ED6560.png
 
Haven't seen the direct answer - the WSJ reports he ran out of air. For someone in good shape but working hard, that is probably less that 2 minutes to losing consciousness.
 
G-force said:
This is what it looks like to cave dive. It is seriously no joke, the slightest error or equiptment malfunction and you have little options, even with a buddy feet away from you. Now, try and drag someone who has never dove and can't even swim through this? I hope is all works out, but if someone panics while diving, they are probably going to die.
Click to expand...

Nope nope nope! Not even a little bit. I got claustrophobic just watching that. Efff That!
 
JCranford said:
Nope nope nope! Not even a little bit. I got claustrophobic just watching that. Efff That!
Click to expand...

Not to mention that the visibility in the cave is basically 0. I used to think my worst nightmare was being covered in snakes....but this easily surpasses that.
 
flyingron said:
Actually you have to make a slight negative pressure to inspire to make the regulator flow (short of pushing the purge button). You don't breath out against the regulator pressure.
Click to expand...
Yes, the second stage has a very slight "cracking" pressure. But it's pretty trivial on quality regs. Just enough so it doesn't free flow. And if you read my post and the one I was responding to, you'll see he was saying the opposite. The reg does not fill your lungs under pressure. The purpose of the second stage regulator is to take the gas from the intermediate pressure and deliver it at ambient pressure.
 
cgrab said:
Normally you breath in and the weight of your body and the relaxed state of your muscles exhales the CO2. In SCUBA, the air is under pressure and fills your lungs then you have to force the CO2 out. You have to train your body to do it but it is still very taxing.
Click to expand...

Breathing out against a CPAP machine requires FAR more pressure than breathing out against a SCUBA regulator, and obviously people can wear CPAPs for many hours a day, years on end.

Neither is really taxing.
 
This is hardcore cave diving. I have done about 10 instructional cave dives in Florida but this one is by far more intense than anything mentioned or discussed.

The team in Thailand is facing a similar tight squeeze to get in and out of the cave as I understand the graphics i have seen. @G-force nailed it when he says No room for error or panic.

G-force said:
This is what it looks like to cave dive. It is seriously no joke, the slightest error or equiptment malfunction and you have little options, even with a buddy feet away from you. Now, try and drag someone who has never dove and can't even swim through this? I hope is all works out, but if someone panics while diving, they are probably going to die.
Click to expand...
 
To answer 6PC's question...

I've never experienced it myself, but from what I've heard, breathing from an empty scuba tank is like trying to suck air from an empty Coke bottle.

I'm interested to know what really happened with the diver. Glad the 1st four kids make it out yesterday. Hope the rest make in out in the next couple of days. Can't wait for the movie to come out on Amazon Prime.
 
G-force said:
This is what it looks like to cave dive. It is seriously no joke, the slightest error or equiptment malfunction and you have little options, even with a buddy feet away from you. Now, try and drag someone who has never dove and can't even swim through this? I hope is all works out, but if someone panics while diving, they are probably going to die.
Click to expand...
I swear I got claustrophobic just watching this guy enter the cave.
 
I saw that they were quarantining the kids that got out in case they picked up anything in the cave. Does anyone have any idea what specifically they might be concerned about medically?
 
Wait so if it is so tight how are they getting the kids out?
 
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