Diver lost in 100' off Juno Beach, FL

[DandyDon]

Scubagalpal, thanks for giving us first hand observations; I'm sure it was difficult to even paste over for us here. I'm sure others have already assured you that you should feel no blame here, but I'd like to add my voice to that. Sounds like you were all competent divers for the conditions, and we know all too well how a diver can slip out of slight in a few seconds of task tending. It's amazing and unfortunate that something like this could happen to one such as Eve.

 

[fairybasslet]

Hi Pat. It's me. Ellen (wrong gate). Just wanted to give you a hug again.:grouphug:

 

[Seadeuce]

Another thing that possibly could have happened is that having a mixture of 30% at that depth could have thrown her into a CO2 overload, thus not alerting her to any LOA or OOA possibilities. Again, I would not presume to infer that this is the case, but I believe that the purpose of this type of thread is for others to learn what can go wrong to prevent tragedies like this from occurring again, if possible.

Please explain your thinking here. I would like to understand how a Nitrox mix could lead to a CO2 buildup.

In any case, what a tragedy. My heart goes out to her, and to those left behind.

Thanks,


Seadeuce

 

[danvolker]

Please explain your thinking here. I would like to understand how a Nitrox mix could lead to a CO2 buildup.

In any case, what a tragedy. My heart goes out to her, and to those left behind.

Thanks,


Seadeuce

The deeper you go, the more that higher CO2 levels ,from exertion, can cause Oxygen toxicity reactions--ie, seizure and blackout....

If she was using a tank she had not analyzed, that was significantly higher in O2 than the 32%, then this could have made even a small increase in CO2 level dangerous....also, the deeper you are ( particularly deeper than 80 feet), the harder it is for your body to rid itself of CO2...At 115 feet, many people can not increase work effort beyond minimal effort, without a large increase in CO2.

Things like stress will increase Heart Rate and CO2 levels in the blood--could be stress from anxiety in losing sight of buddies in murky water, of having a bunch of sharks circling in murky water, could be working too hard to get off the bottom, causing CO2 buildup--as in being negative on the bottom, and swimming too hard for your body to eliminate the CO2 quickly enough...narcosis is increased with elevated CO2 levels, which can lead to more exertion by not thinking about consequences--then higher still CO2, or can lead to more anxiety--because feeling narced can sometimes make people uncomfortable....
All these are possibilities, and these could also have had no bearing on what actually happened.

My condolences to her friends and family.

Dan V

 

[Seadeuce]

Thanks for the reply. I fully understand how the CO2 hit happens, having suffered same once.

What I don't understand is how the extra O2 can make one more susceptible to the hit, any more than air can.

Surely the higher concentration of O2 in the bloodstream would mean that a hit would take longer to happen.

The OP also mentions that she may have been less alert to an OOA or LOA due to CO2.

If CO2 comes on the first thing you would do is to check your air!
Also, CO2 would begin after, as you rightly said, some exertion that would lead to rapid breathing.
But this rapid breathing is shallow, hence the CO2 buildup, and as such would not make you consume much more than if you were breathing normally. Remember - rapid but shallow breaths. Lower volume breathing that is.

Anyway, to state my understanding of it - and why I posted this inquiry - I believe that you are no more at risk from CO2 using Nitrox than you are using air.
The effects of CO2 would be the same in either case, and would be brought on by the same factors - exertion etc.

But! Using Nitrox ( at the appropriate depth for the mix of course) would be a safer option, would render you less likely to be narced, and would make you MORE alert where OOA and LOA is concerned.

I made the inquiry because I didn't want ppl to form a wrong opinion.

In this sad case I would hope it was medical rather than diving-related.

Cheers again

Seadeuce

 

[LunkerBuster]

rest in peace eve....Seems like a hell of a lady.

i just heard over on spearboard and wanted to read the account from scubagalpal...thanks for sharing.
hopefully this tragedy will yeild some info that can help us all avoid such sadness again in the future

 

[DandyDon]

But! Using Nitrox ( at the appropriate depth for the mix of course) would be a safer option, would render you less likely to be narced, and would make you MORE alert where OOA and LOA is concerned.

Don't think so, since O2 can also have a narcotic effect at depth. Studies disagree.

Nitrox does one thing: Reduces N2 absorption.

 

[rknazik]

Thanks for the reply. I fully understand how the CO2 hit happens, having suffered same once.

What I don't understand is how the extra O2 can make one more susceptible to the hit, any more than air can.

Surely the higher concentration of O2 in the bloodstream would mean that a hit would take longer to happen.

The OP also mentions that she may have been less alert to an OOA or LOA due to CO2.

IMO, more likely an O2 toxicity hit. 32% mix, dive around 120' gives a PPO of around 1.5. Dive length was greater then 35 minutes. All this gets real close to the maximum recommended O2 exposure limit. Remember that the average O2 analyzer is only accurate to within about 1%, so her mix could have been even a bit higher. Diver's have toxed at 1.4 PPOs. From the description it seems she slipped to the bottom very quickly, which doesn't seem to fit the pattern for a CO2 hit, but does for O2 toxicity. Generally divers are somewhat confused before they pass out with CO2, while with O2 toxicity a diver can be fine one second and then immediately convulse and drown. Rest in Peace Eve.

 

[ScubaSteve]

.....But this rapid breathing is shallow, hence the CO2 buildup, and as such would not make you consume much more than if you were breathing normally. Remember - rapid but shallow breaths. Lower volume breathing that is.......

While this may be true, the rapid shallow breathing does not allow the body to expel the CO2 from the system properly thus encouraging the buildup. You may not take as much in but you do not get rid of everything you take in.

 

[danvolker]

What I don't understand is how the extra O2 can make one more susceptible to the hit, any more than air can.
Surely the higher concentration of O2 in the bloodstream would mean that a hit would take longer to happen.

The issue here is that higher pressure O2 in the blood, can/will become toxic at some point--and that 32 % Nitrox would be more dangerous than air for this specific O2 toxicity issue.

The OP also mentions that she may have been less alert to an OOA or LOA due to CO2.

High CO2 can make the effects of nitrogen narcosis more accute, so more narc can mean less awareness of important issues like how much gas you have left, or how hard you are swimming.

If CO2 comes on the first thing you would do is to check your air!

Not necessarily, it could just mean harder breathing and more narcosis, and then less checking of critical issues....But often, it would mean some level of anxiety increase , more stress. The only good solution to fix this fast, is to ascend --even up to 30 feet or less, where you can rid yourself better of CO2.

Also, CO2 would begin after, as you rightly said, some exertion that would lead to rapid breathing.
But this rapid breathing is shallow, hence the CO2 buildup, and as such would not make you consume much more than if you were breathing normally. Remember - rapid but shallow breaths. Lower volume breathing that is.

High CO2 on a dive can easily come with rapid deep breathing...if the person is at all athletic, this would be what you would expect. And an athlete with good cardio will rid themselves of CO2 far better than their sedentary evil twin would, at any given depth....

Anyway, to state my understanding of it - and why I posted this inquiry - I believe that you are no more at risk from CO2 using Nitrox than you are using air.

Wrong. The issue here is depth...a diver getting to the limit of where a Nitrox mix is safe ( due to ox tox). High CO2 levels will cause the oxygen toxicity to occur at lower PP of O2 than normal.....and air has much lower PP of O2 for this deep dive than does 32% Nitrox...

But! Using Nitrox ( at the appropriate depth for the mix of course) would be a safer option, would render you less likely to be narced, and would make you MORE alert where OOA and LOA is concerned.

You should not expect Nitrox to reduce narcosis significantly, so no , I would not expect it to help with the OOA or LOA problems....you use Nitrox so that you end up having less nitrogen go into solution in your blood, during a dive ( because it has LESS nitrogen in it than air does--oxygen makes up for the volume of nitrogen that is absent--but too much oxygen gets toxic at depth, so Nitrox is not the big panacea for deeper diving....). And the amount of nitrogen is still high enough to cause plenty of narcosis...the way around this is to pump helium into the mix, drastically reducing the amount of nitrogen left for narcosis effects--and still keeping oxygen levels optimal for planned depth. For the Hole in the wall, we have a mix called triox, or hyperoxic trimix, that allows you to dive it like air or nitrox ( no gas changes needed), and it will provide you with an equivalent narcotic experience on a 150 foot deep dive, to an air or nitrox dive of perhaps 50 feet deep. Most divers who try this mix, and who thought they were sharp at 140 feet down, are amazed at how much more they experienced when diving the triox mix....!