Freediving Death...

[deep thinker]

Thing about blacking out so deep is that your normally negatively boyant, so you dont go afloat like you would when blacking out in shallow water, guess thats where the hand on a loosened weight belt comes in, dont know if youll float from there though even if you dont have a weight belt on.
Bill did your buddy make it?

 

[Bill McIntyre]

No he didn't.

 

[deep thinker]

Sorry to hear, its always a pity when freinds leave so unexpectedly. Im still in the fortunate position not to have lost a diving buddy and I hope I never will...
Atleast we get to do what we love

 

[trux]

I disagree. Shallow water blackout is a blackout which occurs near the surface, during the ascent from a deep depth (>5m). Deep water blackout is a blackout which occurs in the deeper phase of the dive, typically on the bottom or the very early part of the ascent....

Although I used to think the same, it is apparently not the case. At least not according to the definition published in Wikipedia. If you absolutely disagree with them, and know about official references denying their definition, you should consider editing the Wiki records of [ame="http://en.wikipedia.org/wiki/Shallow_water_blackout"]SWB[/ame] and [ame="http://en.wikipedia.org/wiki/Deep_water_blackout"]DWB[/ame].

They specifically address this contraversion in a separate chapter, so their definition is certainly not there by hazard or mistake:

In some places, notably in US scuba diving open water curricula, a blackout from a deep freedive is sometimes referred to as a shallow water blackout. Where this happens there is usually little or no discussion of the phenomenon of blackouts not involving depressurisation and the cause may be variously attributed to either depressurisation or hypocapnia or both. This problem probably stems from the original identification of the mechanism of latent hypoxia arising in the context of a string of fatal, shallow water accidents with early military, closed-circuit rebreather apparatus prior to the development of effective partial pressure oxygen meters. In the very different context of dynamic apnoea sports careful consideration of terms is needed to avoid potentially dangerous confusion between two phenomena having different characteristics, mechanisms and prevention. The application of the term shallow water blackout to deep dives and its subsequent association with extreme sports has tended to mislead many practitioners of static apneoa and dynamic apnoea distance diving into thinking that it does not apply to them even though true shallow water blackout kills many swimmers every year, often in shallow swimming pools.
Some consider deep water blackout to be a special condition or subset of shallow water blackout, which is more accurate and may be acceptable. However, in the interests of accuracy, clarity, helpfulness and safety this article treats the two as separate phenomena with the following characteristics:

• Deep water blackout occurs as the surface is approached following a breathe-hold dive of over ten metres and typically involves deep, free-divers practicing dynamic apnoea depth diving usually at sea. The immediate cause of deep water blackout is the rapid drop in the partial pressure of oxygen in the lungs on ascent.

• Shallow water blackout only occurs where all phases of the dive have taken place in shallow water where depressurisation is not a factor and typically involves dynamic apnoea distance swimmers, usually in a swimming pool. The primary mechanism for shallow water blackout is hypocapnia brought about by hyperventilation prior to the dive.

This confusion is exacerbated by the fact that in the case of deep water blackout hypocapnia may be involved even if ascent is the actual precipitator.

 

[Bill McIntyre]

Wikipedia is wrong. Every explanation of SWB that I have ever read conforms to Eric's description.

Or to put it another way, if Eric is wrong, then he sure is in good company.

 

[trux]

I do not think it is wrong. It only became standard among freedivers to call the events by the wrong names and hence now it is difficult to change the bad custom. However, the original definition was indeed differentiating between SWB and DWB, where the principal difference is the depressurization at DWB, and not the depth where the BO happens. I am certainly aware that when freedivers speak about SWB, they in fact mean BO (primarily) due to the depressurization, hence DWB. It does not mean yet it is correct, but the principal is that we know what we are speaking about - the naming convention is then secondary, indeed.

 

[mn.psyc]

1. Hypoxia blackout (low oxygen)
2. CO2 blackout (too high CO2)
3. N2 blackout (too high N2)
4. Hyperoxic blackout (too high O2)

Eric could you write a little more about the mistakes that can lead a freediver/spearfisher into CO2 blakout and the physiology of this type of blackout?

I think i ve read in a paper that arterial blood CO2 partial pressure doesnt show pressure-induced increase at depth (unlike pO2). Shouldnt that be against a CO2 blackout from too high CO2 ?

And what about FRC diving? Is such a style more prone to CO2 blackout?

 

[Paul Kotik]

Jon's made a great point: getting killed diving is very rude and inconsiderate of others. If it were something only the diver suffered, it would be strictly his business. But it isn't.

Somebody always has to clean up afterward.

 

[trux]

Wackass, you may want to read this document: "CO2 Acclimatization - Acclimatization You Don't Want - Carbon Dioxide". Although written especially with scuba and rebreathing diving on mind, I think it is very interesting for freedivers too, especially those who also scuba dive or use rebreathers. It brings questions what the impact of training CO2 tables really is, and how it can influence the risk of blackouts. It writes for example this:

Many attempts have been made to identify carbon dioxide retainers. Such people could be at unexpected risk of CO2 blackout, unusual degrees of nitrogen narcosis, or susceptibility to oxygen toxicity. Identification, for that reason, would be a helpful screening.

BTW, there is also another definition of Shallow Water Blackout and some historical background:

The term "shallow water blackout" was used in 1944 by Barlow and MacIntosh (9) for blackout suspected, and later confirmed, from too high CO2 levels (hypercapnia). It was termed "shallow water" because oxygen rebreathers could not be used in deep water because of the high oxygen content. Most of the cases weren't deep enough to have been O2 toxicity, which had previously been the prime suspect. The problem subsided after improving carbon dioxide absorption canisters. Although the term "shallow water blackout" had the established meaning of CO2 retention-induced blackout, it was later applied to unconsciousness from too low oxygen (hypoxia) in breath-hold diving, especially following excessive hyperventilation. The mix-up has continued into common use.

 

[Fondueset]

There was a little twist in this thread and I just want to clarify something. It appears to me that this thread is about Risk Mitigation.

One of the givens that has come into play is that most of us do not dive recreationally with a strict buddy structure. When this 'cat came out of the bag', as jome observed, we began to get away from absolutes and 'shoulds' - and were empowered to freely discuss our discoveries and mistakes and to learn from others. The thread really started to bear fruit in a more dynamic way.

I'm also in agreement with Eric's definitions of SWB and DWB - they contain wiggle room with regard to specific causes and make practical sense in the context of freediving.

 

[Bill McIntyre]

Jon's made a great point: getting killed diving is very rude and inconsiderate of others. If it were something only the diver suffered, it would be strictly his business. But it isn't.

Somebody always has to clean up afterward.

Tell me about it. First I had to try CPR looking at his eyes rolled back up in his head, and with bloody mucous and foamy water coming out of his mouth and nose with every compression. It ain't like the dummy that you used to get certified. It tasted so bad that I couldn't get rid of it for two days. I had another friend who was trying to alternate with me, but he couldn't hack it and backed away.

Then I had to make the decision to quit trying. I know that you are supposed to keep at it until the professionals arrive, but there was no coast guard and no helicopters, and we were 90 minutes from the dock. There was no way I could keep it up in a bouncing open boat. I figured he wasn't coming back, so then we sat and looked at the body during the long boat ride home.

Then the hardest thing I've ever done was to pick up the phone and call his wife, the mother of his five children. I'd still be sitting there if an employee of the Cortez Club had not picked up the phone, dialed, and handed it to me.

I spent most of the night going from office to office in the Judicial Police Headquaters sitting under single bulbs being asked questions in Spanish with Andrea Tomba of the Cortez Club translating and telling me where to sign.

Then we had to get the body home. You can't fly a coffin into LAX because of drug smuggling concerns, so it has to cross the border at Tijuana and let funeral homes on each side earn a little bit. The wife agreed to let me get him cremated in La Paz, but of course Andrea had to help me make those arrangements. Then I brought him home in a little box as carry-on luggage. Its a real conversation stopper when someone asks you what is in the box.

By the time it was over, I was through being sorry him and was just mad at him for what he had put me and his wife and kids through.

Sorry for dumping that on you, but it could have been even more graphic. My purpose is to plead with you to do your best to avoid putting your friends and loved ones through that. Your troubles are over, but theirs are just beginning. Even if you don't care about yourself, care about them.

 

[Jon]

Tell me about it. First I had to try CPR looking at his eyes rolled back up in his head, and with bloody mucous and foamy water coming out of his mouth and nose with every compression. It ain't like the dummy that you used to get certified. It tasted so bad that I couldn't get rid of it for two days. I had another friend who was trying to alternate with me, but he couldn't hack it and backed away


I've been there as well. One time it was on a solo scuba diver and the other on a young mother who O.D.'d at a bar that I went to with my students after a night dive. They died both times so my record on CPR is 0 in 2. :head

Lots of paper work and other BS- plus a some sites and sounds that will be with me forever.

I think that once you've seen a few blackouts, and watched a couple of people die, you get a lot more cautious with any of this stuff. Someone mentioned the "butt covering" that was going on, but one of the fears is that someone, most likely a minor, will "Google" this thread and think it's OK to freedive, or scuba dive, solo without any second thought. There are reasons that this is not openly talked about very often, especially in a forum like this, and that's because people DO die and others have to clean up the mess.

Anything mentioned in here are just examples of what people use to fool themselves into think that solo diving is safe and offer no guarantee to anyone- me included.

Having said that I still find it interesting to read what others have come up with for solo diving protocol.

Jon

 

[efattah]

About death:

Your troubles are over, but theirs are just beginning. Even if you don' care about yourself, care about them.

Not too long ago, due to both chemical & situational factors, I went through a period of extreme suicidal depression. Although I was suicidal, I wasn't selfish -- there is a difference. The only reason I didn't kill myself was because I realized the huge amount of pain and suffering that my friends and family would endure. This realization actually made my depression worse, because I realized that as bad as my situation was, I couldn't even escape via death! That was a moment of feeling truly trapped & screwed....

Anyway, I would echo Bill's comment about death being more about your friends & relatives than about you.

 

[Fondueset]

Amazing posts you guys.
Anyone reading this thread will get a very full picture.

 

[fcallagy]

ref what bill and Jon said can you think of any way to make training more realistic. most of the scuba training in cpr etc has been very basic even out of air situations are fairly blase, ie signal out of air pass the reg buddy breath for two etc the best advcie i ever got was from a guy who i was buddied with from another club when i was starting diving he said " you seem like a nice guy and if we have a problem down there and you keep your cool I will share my air with you or try to help you. If you panic and try to rip the reg from my mouth I will take your mask off, punch yu and make my escape" Harsh ? maybe but probably reality if the situation arises.

 

[maytag]

Tell me about it. First I had to try CPR looking at his eyes rolled back up in his head, and with bloody mucous and foamy water coming out of his mouth and nose with every compression... It tasted so bad that I couldn't get rid of it for two days. I had another friend who was trying to alternate with me, but he couldn't hack it and backed away.

Sorry to hear you experienced such horrendous events.

Would a plastic CPR shield have helped even a little? (Bill's situation?) I was under the impression that scuba divers often keep something like that in a pocket. Freedivers could attach it to a dive float.

 

[naiad]

the best advcie i ever got was from a guy who i was buddied with from another club when i was starting diving he said " you seem like a nice guy and if we have a problem down there and you keep your cool I will share my air with you or try to help you. If you panic and try to rip the reg from my mouth I will take your mask off, punch yu and make my escape" Harsh ? maybe but probably reality if the situation arises.

Definitely harsh, but it may be impossible or dangerous to help someone who panics. I haven't heard of too many panic-related freediving disasters, but I have heard of far too many on scuba. Often they are caused by relatively minor things such as a flooded mask, sinus squeeze or minor problems with equipment. People really shouldn't be diving if they are prone to panic attacks in those situations. They are not only risking their own life, but that of their buddy.

Very scary thread. Bill and Jon, sorry to hear of your experiences and thanks for sharing.

Lucia

 

[trux]

Bill, I feel your pain, I feel with you, but there is something disturbing on the story: you seem to be almost upset by the death of your buddy, the "clean up", and all the consequences. As you wrote, "I was just mad at him for what he had put me and his wife and kids through". But, ... and now that's the painful question, ... if you were buddies and each hunting in your own corner, didn't you take just exactly the same risk? Weren't you just "luckier" it happened to him and not to you? Why being mad at him, and not at the common decision to hunt individually without surveying each other? Or did I misunderstood - was it just his own decision to stay alone, and you've been diving together with your other buddy carefully watching each other at every immersion?

Do not take me wrong, this is no accusation - myself I am a lone wolf and do take the risk of diving alone, and even when I dove with friends, I do not think we could have been of a big help to each other if something went wrong. Things changed since I started to train in a club, and studying the topic, but still - I am definitely not innocent as for diving alone goes. However, I find strange getting mad at a dead buddy, when he did just the same as you. Finally, accidents happen, and he could as well slide on a riff and kill himself, or die in a car crash when being with you - it would put you through the same traumatizing experience. Yes, certainly, minimizing risks is important, but there is no way to live safe even if you do not move from your bed at all.

 

[Bill McIntyre]

Bill, I feel your pain, I feel with you, but there is something
disturbing on the story: you seem to be almost upset by the death of your buddy,
the "clean up", and all the consequences. As you wrote, "I was just mad at him
for what he had put me and his wife and kids through". But, ... and now that's
the painful question, ... if you were buddies and each hunting in your own
corner, didn't you take just exactly the same risk? Weren't you just "luckier"
it happened to him and not to you? Why being mad at him, and not at the common
decision to hunt individually without surveying each other? Or did I
misunderstood - was it just his own decision to stay alone, and you've been
diving together with your other buddy carefully watching each other at every
immersion?

Its a fair question.

First, it was a mutual decision to stay alone. It may not be entirely rational,
but I just think he was not as conservative as I was. Sure, an accident could
have happened to me, but I think he was more aggressive and competitive than I am.

In a larger sense, after his death I talked to other guys who had been on trips with him, and they said that he was very competitive about the fish he speared. On the trips he had taken with me on my boat locally, I had not picked up on that, but maybe its because I was so uncompetitive that he didn't consider me a threat. It takes at least two to compete.

But more specifically, I think he was goaded by pride to take chances on this
trip. I had speared just one wahoo in the previous two days of the three-day
trip.(my excuse is that my gun was smaller than their guns), but he had
speared none, while the third guy had speared a few wahoo and a couple of tuna.

We were sharing a hotel room, and after we turned out the lights, the third guy would say something like "I can't believe I got that tuna." It was just mildly annoying to me. In cases like that, I tend to say to myself, "yes, but has he landed a jet on an aircraft carrier." But it was really getting to him, and he told me the next day how much this guy pissed him off.

So on the third and final day, I think he was resolved to catch up. He could do something that the other two of us could not- he could make the deep dives down to the bottom to spear pargo, so he did it. He had already taken a couple before that fatal dive. The pargo is a notoriously powerful fish that always heads for caves and tries to hole up. When I got back and told the story to Jay Riffe, his reaction was "you just don't shoot pargo in deep water without scuba." But he did.

So there it is. I know that its easy to second guess him now and he can't argue with me, but I think his pride lead him to take chances, and it didn't work out. So that's why I was mad at him.

Frankly, I would have been mad at him whether it was justified or not. I was going through such hell myself, and contemplating the effect on his wife and five children, that I was jealous of him for being gone while we had to deal with it.

 

[ocean_314]

Panic is a scary thing when it comes to the ocean weather diving or in boat. During the first couple of big minus tides during abalone season, i see some of the most incredible panic attacks in the water from rookie divers. I saw one woman on a rcok 20 yard from shore in aobut 10' of water so scared that she was shaking in terror. It took 30 minutes to talk her off that rock and into shore. She said that she saw something move in the water. lol
If you want to see a circus come to Ft Bragg Ca. during the major minus tides in the spring. Its fun and amazing. We go just to help out the rookie divers.
Something else that is hysterical. The rookie divers that swallow some sea water. They run on the water trying to get to a bathroom! lolrofl
The bottom line is if you are not comfortable diving and with the ocean you dont dive, never mind dive alone.