Diving incident at Eagles Nest Sink

[cerich]

Well it's for sure speculation. Speculation based off some experience doing long decos and shivering with an intact suit, 8mm hood, 400g thinsulate, and a baselayer.

I could tally up the gas totals and figure out how much time they'd have but it would be really really really cold and I would hypothesize that the deco would be wholly inadequate (due to the cold) resulting in some serious dcs. Combine that with the remoteness and it's just not going to end well.

Have you read the account of the incident in Sweden? Much colder, deco that was easily as long as these guys would have faced.

Even wet in a Drysuits would have been warmer than the Sweden incident for the survivor.

I'm not so quick to dismiss. And while I may not be doing these long exposure dives because I haven't had to deal with a emergency that put me into that bad of a deco deficit (nor am I pushing things as much anymore) I have done lots of over 2 hour cold water deco in much colder water than Florida springs, including with wet undergarments that made it beyond miserable.

 

[cerich]

Don't take the breather off was the good choice in this case

We are in complete agreement. My comments on Drysuits flooding for buoyancy were based on the chain of events after that decision was made. All I can think is he was jammed, couldn't breath on the unit because his counter lungs were space compromised and he saw no other choice....but yeah, once the unit came off the possibility of a good outcome went from bad to miracle

 

[cerich]

Ok about to take off and four hour flight...take care all!

 

[PfcAJ]

Have you read the account of the incident in Sweden? Much colder, deco that was easily as long as these guys would have faced.

Even wet in a Drysuits would have been warmer than the Sweden incident for the survivor.

I'm not so quick to dismiss. And while I may not be doing these long exposure dives because I haven't had to deal with a emergency that put me into that bad of a deco deficit (nor am I pushing things as much anymore) I have done lots of over 2 hour cold water deco in much colder water than Florida springs, including with wet undergarments that made it beyond miserable.

Yeah and I think they had heated vests. Game changer.

Keep in mind that these guys had 1 canister between the two of them (size unknown) so right there you're limited to an hour or two of heat tops if they even had vests, and I'm not sure they did.

 

[cerich]

Th

Yeah and I think they had heated vests. Game changer.

Keep in mind that these guys had 1 canister between the two of them (size unknown) so right there you're limited to an hour or two of heat tops if they even had vests, and I'm not sure they did.

Sweden one his vest died and he had hours with no vest heater..still colder than wet in Florida.

Ya know what? This whole thing just sucked.... :-(

 

[Dan]

We are in complete agreement. My comments on Drysuits flooding for buoyancy were based on the chain of events after that decision was made. All I can think is he was jammed, couldn't breath on the unit because his counter lungs were space compromised and he saw no other choice....but yeah, once the unit came off the possibility of a good outcome went from bad to miracle

The diver2 CCR found in good working order.

 

[RainPilot]

For me the value of speculation is NOT trying to find out what actually happened on the incident dive. That will be done by people way more qualified than me. I find much more value in looking at the known facts and then looking at possible causes, especially looking at "why" the divers may have made the decisions they did and how that affected the outcome. I KNOW that we will never know the objective truth but an insight into possible thought processes and event cascades leads me to re-evaluate my thinking on potential scenarios that may affect my diving.

So far my thoughts on this, working from @netdocs comment on the possibilities of a drysuit flood and the reactions of the other members here:

Fact: There was an issue with too much buoyancy.

Conjecture: Why? It seems that the removed CCR unit was contributing a lot of weight to the divers system with insufficient separate weight to compensate for the drysuit.

Applicability: My CCR is VERY floaty indeed. In an effort to reduce my total weighting I have gone for a thick steel backplate and a lot of non-ditchable trim weights. With the unit on, I am in a balanced rig BUT I had never considered removal of the unit underwater. Since I dive mostly with very little thermal protection it will be ok but if I ever go thicker / dry I will need to distribute the weight better in case of a removal scenario.

Conjecture: Anything that could have been done to offset the buoyancy? Yes, he could have flooded his drysuit (partially?) to help compensate. Why didn't he? he was an experienced skillful cave diver by all accounts so either he didn't consider the possibility (stress etc) or didn't think it would be necessary or felt that the risks outweighed the benefits. From the reactions of other members it seems that he would have been of a mindset that flooding would lead to severe issues with his deco later. However, he would also know that DCS might be treatable but drowning isn't. That leads me to believe that he didn't believe that he would completely run out of gas. In conjunction with the safety that they had placed that seems to be a reasonable assumption on his part. However, when he couldn't get that safety things became irrecoverable.

Applicability: I dont dive with placed stages at this stage of my diving but it is coming soon. I need to decide whether, if I have an emergency before getting back to my stage, I should act and plan as if I won't get back to the stage or whether reliance on it is ok. We were always taught in survival training that in an egress-from-aircraft situation "If it is not on your person then you dont have it" i.e. dont rely on the grab bag behind the seat for essential gear, when you bolt you may not have time to get it. In this instance, the safety bottles are redundancy but there is still a single point of failure. The positioning. It doesn't matter how many stages and safety you have in one basket if you cant get to them. Would this be something to consider?

Would building in some redundancy in positioning of safety bottles be something positive that might come out of this? i dont know enough about cave diving but it seems that if a "suitable spot" might become untenable, maybe spreading the goodness? For example, it seems that they left safeties at the exit of a restriction which they didn't get to. What would have happened if they put one safety at either side of the restriction?

 

[uncfnp]

Out of my depth here and hesitate to intrude but...

Yes hypothermia can increase risk DCS but hypothermia has also been associate with increased survival in cold water drowning and is even used therapeutically in some cardiac arrest situations. Might it not have some of the same benefit here?

Obviously an act of desperation.

 

[The Chairman]

surely you see the differences between you and your dives and these guys and thei dive right?

Surely, you don't see me diving Eagles Nest. Been invited a number of times... still not ready nor qualified. But let's look at the Science. According to this article A diver may last any where from 3 hours to indefinitely before experiencing hypothermia in water between 70 and 80 degrees. And yes, more fat means more warmth. Ever see a skinny manatee?

I would hypothesize that the deco would be wholly inadequate (due to the cold) resulting in some serious dcs.

So, you're suggest that DCS would not be preferable to death? I would contend that 'serious' DCS would be preferable to dying while still warm.

 

[PfcAJ]

Surely, you don't see me diving Eagles Nest. Been invited a number of times... still not ready nor qualified. But let's look at the Science. According to this article A diver may last any where from 3 hours to indefinitely before experiencing hypothermia in water between 70 and 80 degrees. And yes, more fat means more warmth. Ever see a skinny manatee?


So, you're suggest that DCS would not be preferable to death? I would contend that 'serious' DCS would be preferable to dying while still warm.

I'm suggesting that dcs would probably result in death.

The situation was no longer survivable the second the diver lost the ability to get back into his rebreather.