Ginnie Springs diver missing - Florida

[tbone1004]

@rjack321 i think swapped hypoxia and hyperoxia in that post. Shutting off O2 would be the wrong answer to hypoxia

 

[bada3003]

... I'm still chalking this most recent death up to lack of a HUD though. Lots of contributing factors at play, but ultimately, it was not paying attention to PO2 that lead here, and a HUD is such an easy way to catch an unsafe condition while it's still recoverable.

Unless I missed some known facts surrounding the diver's death, your conclusion is not logical. Given the age of the diver, and the general stats surrounding the causes of diver fatality, in the absence of further information health issue is a primary culprit.

Secondly, given the experience level of the diver, it seems unlikely that the diver failed to check PO2 for an extended period that led to his death. Even when exploring 5000-6000 feet in the Devil's cave system. More likely hypercapnia which can strike experienced and inexperienced divers alike.

Then perhaps hyperoxia, and possibly other factors.

There are only so many ways one can die cave diving. Unless there is a genuinely new factor for which there is no indication, which of the likely factors contributed to the diver's death is not terribly informative. However, concluding that not having a HUD played a primary role is illogical given the available information.

 

[helodriver87]

Unless I missed some known facts surrounding the diver's death, your conclusion is not logical. Given the age of the diver, and the general stats surrounding the causes of diver fatality, in the absence of further information health issue is a primary culprit.

Secondly, given the experience level of the diver, it seems unlikely that the diver failed to check PO2 for an extended period that led to his death. Even when exploring 5000-6000 feet in the Devil's cave system. More likely hypercapnia which can strike experienced and inexperienced divers alike.

Then perhaps hyperoxia, and possibly other factors.

There are only so many ways one can die cave diving. Unless there is a genuinely new factor for which there is no indication, which of the likely factors contributed to the diver's death is not terribly informative. However, concluding that not having a HUD played a primary role is illogical given the available information.

At the risk of stepping on toes, I'll tell you it wasn't a health thing. That was my first thought too and it's a reasonable assumption, but this was a proper accident.

 

[rjack321]

At the risk of stepping on toes, I'll tell you it wasn't a health thing. That was my first thought too and it's a reasonable assumption, but this was a proper accident.

I'm not especially concerned about stepping on toes. But as far as I can tell...

Diver was relatively new to CCR (certified in the last ~3-4 years)
Sidewinder was his 2nd CCR, started on an SF2
Diver was surveying in low, silty cave off the current maps
Age was late 50s or early 60s but not an obvious factor
No HUD on the unit
DSV was still in his mouth
Bailouts were full and diver still had O2
O2 was shut off with an in-line slide

Feel free to correct any inaccuracies.

 

[helodriver87]

I'm not especially concerned about stepping on toes. But as far as I can tell...

Diver was relatively new to CCR (certified in the last ~3-4 years)
Sidewinder was his 2nd CCR, started on an SF2
Diver was surveying in low, silty cave off the current maps
Age was late 50s or early 60s but not an obvious factor
No HUD on the unit
DSV was still in his mouth
Bailouts were full and diver still had O2
O2 was shut off with an in-line slide

Feel free to correct any inaccuracies.

All of that is accurate to my knowledge. Best guess prior to learning about that technique of shutting off O2 to breathe down a slightly hot loop was accidental closure of inline shutoff compounded by lack of PO2 monitoring due to survey distraction. Either way, hypoxia seems to be the obvious culprit. Why the inline shutoff was closed might be hard to narrow down. If the log shows a slightly hot loop followed by a steady decline, intentional shutoff is a reasonable assumption. Whatever happened, he never attempted to bailout. So he was likely unaware of his PO2. Maybe he doesn't catch that even with a HUD, but his chances are far better with a difficult to ignore alarm.

 

[bada3003]

At the risk of stepping on toes, I'll tell you it wasn't a health thing. That was my first thought too and it's a reasonable assumption, but this was a proper accident.

Thanks for the clarification. If health wasn't a factor and O2 inline shut-off was closed (I missed this bit), then both hypercapnia and hypoxia seem possible contributing factors. Among others.

By default, I would still doubt that an experienced diver wouldn't have awareness to check PO2 for an extended period. It's certainly possible if you're in a restriction and task loaded.

Another possibility is hypercapnia, reduced mental acuity, with resultant negative consequences. Whatever the case, they seem to fall within the realm of what can happen to anyone on a bad day.

 

[tbone1004]

Thanks for the clarification. If health wasn't a factor and O2 inline shut-off was closed (I missed this bit), then both hypercapnia and hypoxia seem possible contributing factors. Among others.

By default, I would still doubt that an experienced diver wouldn't have awareness to check PO2 for an extended period. It's certainly possible if you're in a restriction and task loaded.

Another possibility is hypercapnia, reduced mental acuity, with resultant negative consequences. Whatever the case, they seem to fall within the realm of what can happen to anyone on a bad day.

I would argue that he was possibly on top of the curve. Just far enough from new diver to not be terrified, but hadn't had a bad enough near miss to have a healthy respect for it.
Either way I don't think the HUD would have done much of anything. Haptic feedback probably would have, but I don't know if a HUD would have without knowing the conditions.

 

[rjack321]

All of that is accurate to my knowledge. Best guess prior to learning about that technique of shutting off O2 to breathe down a slightly hot loop was accidental closure of inline shutoff compounded by lack of PO2 monitoring due to survey distraction. Either way, hypoxia seems to be the obvious culprit. Why the inline shutoff was closed might be hard to narrow down. If the log shows a slightly hot loop followed by a steady decline, intentional shutoff is a reasonable assumption. Whatever happened, he never attempted to bailout. So he was likely unaware of his PO2. Maybe he doesn't catch that even with a HUD, but his chances are far better with a difficult to ignore alarm.

An O2 shut off is not stock supplied equipment on a Kiss.

Its fairly common to add one on sidewinders since accessing the butt mounted O2 is a challenge for non-monkeys. Cave oriented SW classes (kinda what the sidewinder is actually good at) seem to bring up sliding off the O2 and breathing down the loop vs dil flushing. Especially when you're using 32% as BO/dil, flushing down can take quite a bit of gas at 100ft. If it's not crazy high, slide of the O2 and "just" breath it down. It was part of my crossover and my O2 was also (obviously) off for my SCR exit too.

I don't have a precise handle on how common this <O2-off-breath-it-down> approach actually is or if that's exactly what happened here. My gut feeling is it's fairly commonly taught on the sidewinder in particular- in this case it would be an especially bad idea without a HUD or NERD. With normoxic or worse hypoxic BO/dil in a shallower section of a cave, it gets worse still because if you breath down the loop and your ADV fires, the ppO2 can drop faster and further pretty quick.

Whereas if you're diving 21/35 or 18/45 in the back of Ginnie and happen to be at 100ft at the time you see 1.4, a quick squirt of dil with the MAV is a much quicker and safer way to get back down to ~1.1 compared to breathing it down.

 

[rddvet]

cue one of the myriad of reasons that I think eCCR's are much safer. Parachute mode on eCCR is the bomb. I do not enjoy when my mCCR gets up to 1.5 or 1.6 and I have to wait to breathe it down with the O2 shut off. The needle valves don't make it any better because you still have to turn them back on. I've never been able to see an advantage of mCCR other than cheaper and easier to manufacture. I admittedly own two of them, but it's a big point of contention I have with them.

for my education, why would you shut off oxygen and breathe it down. I was taught if it s a little high breathe it down. But if it’s that high I was always taught dil addition or dil flush. I personally wouldn’t want an in-line shut off on my oxygen. I believe when I did the sidewinder course there was a shutoff on the oxygen and I wasn’t a fan. But ai don’t remember Edd teaching me to shut off the oxygen and breathe it down. And definitely wasn’t taught to in the fathom course. So what would the benefit of breathing it down be other than avoiding having to dil flush or avoiding wasting oxygen.

 

[tbone1004]

for my education, why would you shut off oxygen and breathe it down. I was taught if it s a little high breathe it down. But if it’s that high I was always taught dil addition or dil flush. I personally wouldn’t want an in-line shut off on my oxygen. I believe when I did the sidewinder course there was a shutoff on the oxygen and I wasn’t a fan. But ai don’t remember Edd teaching me to shut off the oxygen and breathe it down. And definitely wasn’t taught to in the fathom course. So what would the benefit of breathing it down be other than avoiding having to dil flush or avoiding wasting oxygen.

If you don't shut off the O2 it can take 20+mins to breathe it down from 1.6 back to 1.1 depending on depth.

If you believe in hot dil and are at depth, then you may have an issue. When I'm in Ginnie/LR/JB/etc on EAN32 my ppO2 actually goes up when I dil flush since I run 1.1 but the dil ppO2 is 1.2-1.3.