Lessons learned - a SWB Story

[BatRay]

How should we then dive? I mean, Willer took reasonable precautions, and still he blacked out, and he was without a buddy. People can black out with buddies and it can be a close call. You're taking a big risk either way, but where does the risk really lie? Is it mostly an issue of overconfidence? If so, at what point does it become overconfidence? I confess this whole issue confuses me, because there doesn't seem to be a solid way to take safety precautions.

Or maybe I just need to take the PFI courses...

 

[BennyB]

I think that we have to look at a couple of things here. First, every time we jump in the water we have to accept a certain level of risk. Second, we have to understand that some things we can influence, some we cannot. After Colin's experience it's reasonably clear that you cannot 100% control the factors that lead to blackout. Therefore we should always assume blackout as a scenario that will happen at some point. The risk actually lies with the blackout recovery, not the blackout itself. The way you handle the recovery is the way you control the danger to yourself.

It's only when that point is accepted that you can start looking at safe water practices (ie. bottom line is don't dive alone).

 

[jome]

Benny, that must be one of the best posts I've read on deeperblue...

 

[jome]

I think if you take Eric's (wise) personal point of view "Always ASSUME like you're diving alone and make your divers according to that assumption" and Benny's Organizational point of view (I consider a buddy pair to be an organization) of "Always ASSUME there is a black out and be prepared to handle it".

If all divers followed that advice - we'd see a lot less fatal or serious accidents. Preferably both, but even one would already be an improvement.

 

[azapa]

excellent points. Assume you have to watch your own a.s even when with a "buddy"

Snorkel question bearing that in mind: surface with or without as part of drill? Looks like it may have saved Amphibious?

Scenarios:
1. surface BOed, fall flat on face or remain vertical (probably a little negative after pre-surface BO exhale): no snorkel, no larygospasm and you'll suck water
2. surface BOed, fall on back (can't see it happening unless weight belt ditched), with snorkel in and you'll suck water, without and your fine.

Interesting to hear Amphibious mention that he sometimes replaces snorkel in mouth just before surfacing..

Opinions?

 

[Fondueset]

First - I agree with Benny and Eric; Theres no room for fundamentalism in freediving.

I'm very much enjoying the analysis taking place in this thread. I think understanding everything we possibly can about SWB and all other risks is our responsibility as divers.

I dive alone frequently. If I didn't I'd hardly dive at all; and I love to dive. I mitigate risk by diving shallow and doing long dives only when I am well rested, relaxed and able to really feel myself. Since I am often engaged in the very focused activity of photography I have a sort of 'kill switch' in place - a psychological mechanism that helps me let go of even the most perfect pending composition when its time to surface. While surfacing I relax and focus within - making my movements as relaxed and efficient as possible; head level but for an initial boat check. I never take the duration of a dive for granted - I never check my times while I am down or dive with the intention of staying down long.

I've noticed any exertion really cuts into my times and requires a longer breathe-up. Even lifting my head out of the water to look around pretty much means starting over again. Since its cold this time of year my breathe-ups tend to be shorter - so I accept the fact that my dives will be short and - particularly if the chill has set in; I'll shift my focus from photography to brief fin sprints.

The Buddy situation is difficult. For Photography having a buddy hovering over me spooks the subjects. Some species here are very wary and will spook pretty much out to the edge of whatever the visibility is.
I am the most competent diver here so I am very conscious of anyone I'm diving with - dives with others are therefor more stressful for me and I generally accept that my times will not be nearly as good. I spend a lot of energy keeping track of where everyone is.

The most relaxing diving I've ever done with my daughter was in Telegraph Cove - Each diver there was stunningly competent but a strict buddy arrangement would've been extremely difficult to implement. We were all there, and checked in with eachother periodically, but we'd have had to be diving on a line to keep track of eachother.

I think breathe ups and the trip up are particular opportunities to focus within and really sense your state. This awareness is, I believe, extremely important when freediving. I also think letting go and accepting everything about the dive and not getting out ahead of yourself are really important.

Its interesting to think about the role of habit in all this. Eric has spoken of giving himself the suggestion to start breathing when he surfaced on the way up from an overextended dive - I think I remember something about him kicking on autopilot too - but could be wrong. Colin mentioned his habit of putting the snorkel back in. It may be that some of these behaviors carry over even as we lose consciousness and it might be that we can, to some extent, program ourselves with optimal surface protocol in the event of a blackout.
You just have to use all of your intelligence actively. The myriad factors involved exceed our capacity to quantify. Freediving is an exquisitely demanding activity.

 

[spaghetti]

Although this may sound pathetic, somehow I feel like I always dive with two buddies: they're my wife and my 3 years old daughter waiting for me at home. They couldn't help in the case of an incident like the one occured to Colin. But so many times, when a fish is too deep or takes too much time to come at range, I hear the voice of my baby saying "please, daddy, let it go".
Pathetic as can be, I know, but it has worked so far.


PS-I agree with what Eric Fattah and Fondueset said, 100%.

 

[surfunc]

We frequently use the buddy system for spearfishing here in Florida, but it's not perfect, and in bad visibility it's impossible to keep track of your buddy, the buddy often keeps their head above water to wait for the diver to break the surface due to the bad vis.

I think the foghorn thing is a great idea and pretty easy to set up, does anyone know of such a product? If the horn is loud and has a sufficient duration (over a minute in length preferably) then it would be perfect here in Florida as we are always within 100 feet of each other.

 

[azapa]

surfunc: i am a big fan of the vest so will defend: the vest is designed to put you on your back

 

[surfunc]

surfunc: i am a big fan of the vest so will defend: the vest is designed to put you on your back

You're right, I was just reviewing their website and see that the design will not allow you to float with your face in the water, thanks for the correction.

 

[hteas]

In all this discussion, unless I missed it, there is one piece still missing. What caused the SWB.

My own SWB, was while diving alone and in a strong current down in Baja. I flared just below the surface and started to clear my snorkel, like normal. Suddenly I was on the surface, snorkel in my mouth and breathing. I was feeling OK, but still knowing something had gone wrong. Very lucky, like everyone else who has had the experience.

The one thing that stood out for me, and is the same variable that Amphibious experienced, is the current. Fighting a strong current causes exertion. Extended exertion causes a decreased sentitivity to CO2. A decreased sensitivity to CO2 can allow you to push your self over the edge and never feel it (at least not until you have lots of practice, like Eric).

In my case, I was pulling myself along the shoreline rocks to get upstream of a small underwater pinnacle. The current was too strong to swim against for long, so I was grabbing rocks to move against it. Then, after breathing up, I'd let go, blast over the pinnacle, hoping to surprise a yellowtail, surface, and swim to shore to start it all over again.

I still dive alone, but am now more sensitive to how my body is working on a given day, including the effects of the environment on me.

Howard

 

[efattah]

TylerZ has developed a great safety protocol during his ascent. Diving with snorkel out of mouth (or no snorkel), as he approaches the surface, he leans back dramatically and basically surfaces already laying on his back. This keeps his airway out of the water.

During a line diving session with him, I spotted him on a deep dive. He looked in trouble on the way up, and despite clearly being foggy headed, he was so used to his method that he did it anyway, landing clean on his back, unconscious and exhaling through pursed blue lips. He woke up very fast, before I even reached his face, and described how he had blacked out, woke up shaking, and then saw me. He would have recovery fine even had I not been there.

In my case, doing FRC dives, one thing which is really on my side is the ability to inhale immediately upon surfacing, without exhaling first. As long as you get that first breath, it doesn't matter if you black out, because you will wake up again when the O2 from that breath reaches your brain. Upon ascending from any type of difficult dive, my sole focus is to optimize and get that 'first critical breath'. Of course, this requires me to dive with my snorkel out of my mouth.

In my whole diving career, the only time I ever had an ocean blackout where I did not get that critical first breath was my first ever blackout which occurred in 2000, where I did so many things wrong I'm embarrassed to even talk about it (extreme dehydration, tried to break pb by 8m, BO from packing, then full breathe up again without any packing, increased weight on belt by 5lbs too much; bottom line, I was excessively dehydrated [low BP], way too hypocapnic, way too overweight, and trying for a huge depth increase all at once.)

Interestingly, as you condition certain habits, as well as increase your brain's tolerance for hypoxia, you can surface and do a good recovery without basic consciousness. In Florida in 2001, when training for the CW record, I surfaced from a 72m dive with total memory loss of the last 8m. According to Kirk, I reached the surface and did a perfect recovery, including the ok sign. My own memory of the dive is blank, all I remember was being at 8m wondering if I was going to make it -- next thing I know I'm looking at Kirk's face, my vision is returning, and I find that my hand is in the 'ok' sign.

 

[dave]

Although this may sound pathetic, somehow I feel like I always dive with two buddies: they're my wife and my 3 years old daughter waiting for me at home. They couldn't help in the case of an incident like the one occured to Colin. But so many times, when a fish is too deep or takes too much time to come at range, I hear the voice of my baby saying "please, daddy, let it go".
Pathetic as can be, I know, but it has worked so far.

That is exactly how I feel. Although I have always been a fairly conservative diver, fatherhood has given me very different perspective on what is important in life
For spearfishing in murky water, a proper buddy system is just not practical (or even possible). As Eric says, thinking you have a buddy to help out can actually make things more dangerous.
Whatever you tell yourself, you WILL push yourself that little bit further if you think there is someone there to save you. I think the phrase is "risk compensation" . Several studies have shown, for example, that drivers will tend to drive faster and more recklessly in cars fitted with ABS than those without, meaning that although the car is "safer" the overall accident rate remains the same.
I have the same reservations about the freedivers safety vest, I think it will encourage people to push themselves further, as they have a parachute to save them

cheers
dave
Spearguns by Spearo uk ltd finest supplier of speargun, monofins, speargun and freediving equipment

 

[Fondueset]

Interesting Eric, While I don't approach the edge of the envelope in my dives I have been getting into surfacing on my back - for one thing its really fun. I use a weight vest but put only 2lbs in it and have the weight in the back of the vest so I tend to surface face up. I've also been implementing the partial exhalation in the last couple of meters so that first breath on the surface is an inhale. I wonder though, if the practice of exhaling on the way up might increase risk of swb?

I think the area of deeply conditioned surface protocols is really interesting. I had an experience like this a couple times during very long drives at night. I started to lose it and when I came back I was carefully pulling of to the side of the road with my turn indicator on.

 

[naiad]

In my case, doing FRC dives, one thing which is really on my side is the ability to inhale immediately upon surfacing, without exhaling first. As long as you get that first breath, it doesn't matter if you black out, because you will wake up again when the O2 from that breath reaches your brain.

One thing I am not sure about FRC diving is does it increase the risk of getting water in the lungs? By creating negative pressure in the lungs, any loss of control could result in water being drawn in.

 

[azapa]

Fondi: the natural (not forced) exhale about 3M before the surface does two things:
a. preps you for an immediate inhale
b. reduces the big drop in partial O2 pressure that you would suffer if exhaling all at the surface, effectively reducing BO chance.
Both these tips are not my own, they are from the FIT II course.
We were taught to perform three hook breaths (breath, hold, release) and three ventilations. As first recovery breaths. The hook breaths also use the upper part of the chest, and that short hold (1 second or so) maintains pressure.

I probably deserve some correction on the above, and would have done better with my course notes on hand.

 

[trux]

Fondi: the natural (not forced) exhale about 3M before the surface does two things:
a. preps you for an immediate inhale
b. reduces the big drop in partial O2 pressure that you would suffer if exhaling all at the surface, effectively reducing BO chance.

Another good reason to do it is to avoid barotrauma / lung squeeze. As discussed already earlier, I believe it is possible that in certain conditions, the inner lung volume can be reduced due to bood shift, so if you dove with full lungs or even packed, the pressure in the lungs at the surfacing could be considerably higher than the initial one and could cause barotrauma.

 

[Fondueset]

When I was a kid I always exhaled the last few meters - back then I kept my snork in and this was an effortless way to clear it.

Great info!

 

[feign]

TylerZ has developed a great safety protocol during his ascent. Diving with snorkel out of mouth (or no snorkel), as he approaches the surface, he leans back dramatically and basically surfaces already laying on his back. This keeps his airway out of the water.

I have been doing a similar thing to end up on my back face up after longer dives when alone by leaning back.

In addition, when I have my normal weight belt, on the ascent I pull the free end of the belt back (in a tightening motion). The rob allen rubber Marseillaise belt is designed so that the central locking pin is "spring loaded" so that when it is not engaged in a hole it flips back and can't re-enter a hole. If I am unconscious and loose motor control of my hand that is holding the belt end, the belt will fall off easily. In this scenario I hopefully end up on the surface on my back even if I am still deep enough to be negative with a belt.

I suppose that if your buoyancy is such that you are still quite deep when positively buoyant, then this may be less useful because you will likely be positive in SWB range. For me I like to be weighted on the heavy side though.

 

[harbour seal]

.....If I am unconscious and loose motor control of my hand that is holding the belt end, the belt will fall off easily. In this scenario I hopefully end up on the surface on my back even if I am still deep enough to be negative with a belt.

i wouldn't but much faith in this idea as men generally float face down when unconcious; however, this notion is easy enough to put to the test. during ascent try releasing your grip at various depths, as you described, and see what happens when you go limp.

cheers,
sean
vancouver, canada