Three dead in Poland last week

[rolanddiver]

Solo divers do not die. The rebreather and cave divers do.

You just don't know what you are talking about.

 

[leadduck]

I don't understand much at all about rebreathers, but if a diver signals some ambiguous distress, switches from his standard life support system to a bail out system, and you are diving in a LAKE, why in the world would the buddy not start an immediate ascent?

Why continue to swim horizontally at a significant depth and continue to rack up more deco time? Even after the deceased seem to show additional stress and difficulty the buddy describes "pulling him downward" and even after the diver watches his buddy have trouble manipulating a BC inflator, he STILL does not initiate an ascent?

They were diving at 44 meters (145 ft) , the decreased goes from a tri-mix to open circuit air and it is obvious that this would induce narcosis and more stress, yet the buddy decides to continue to SWIM horizontally, accrue more deco, further stress the buddy and allow narcosis to set in? And then when he MUST know his decision to not signal an immediate ascent and his buddy MUST be stressed, he doesn't maintain strict contact and then looses him.

Does this description make sense to RB divers? Perhaps my ignorance of the particular gear is hindering my understanding?

Wouldn't an immediate ascent be indicated after the deceased switch from Trimix on the rebreather to narcotic, open circuit air while in deco?

Edit: After more thought...Is it possible the decision was made because DECO oxygen was left way inshore along the bottom, so he didn't want to just start coming up right away ?

I consider a free ascent in a lake in low viz more stressful and incurring a much higher risk of losing each other than swimming near the bottom. Particularly if the distance is short, visibility is very bad and the buddy has problems, then losing him would be my bigger concern, more than deco or narcosis.

 

[johndiver999]

I consider a free ascent in a lake in low viz more stressful and incurring a much higher risk of losing each other than swimming near the bottom. Particularly if the distance is short, visibility is very bad and the buddy has problems, then losing him would be my bigger concern, more than deco or narcosis.

Well I asked for an explanation.. but.. The diver can not operate his rig with one hand and come up slowly... while keeping the other hand ON the victim? It would be easier to keep direct physical contact on the ascent compared to swimming horizontally?

Deeper rebreather divers with oodles of computers can't manage an ascent in dead calm, still water with visibility of 10 feet or so?

An ascent like that (on normal OC scuba) does not sound hard to me. Keeping a guy down on air at almost 150 feet and swimming when he has some kind of problem - medical or otherwise, is more scary to me.

 

[leadduck]

Well I asked for an explanation.. but.. The diver can not operate his rig with one hand and come up slowly... while keeping the other hand ON the victim? It would be easier to keep direct physical contact on the ascent compared to swimming horizontally?

Deeper rebreather divers with oodles of computers can't manage an ascent in dead calm, still water with visibility of 10 feet or so?

An ascent like that (on normal OC scuba) does not sound hard to me. Keeping a guy down on air at almost 150 feet and swimming when he has some kind of problem - medical or otherwise, is more scary to me.

Consider that the buddy had severe problems of unknown nature and may fail to control his buoyancy during the free ascent, may become negative and fall into darkness. So you may have to take control of his wing and drysuit and rebreather, and yours as well, both of you in rebreathers plus stages, he's on bailout already, you have mandatory deco, floating 100ft above ground in <10ft visibility, no boat, no rope, maybe not even a SMB, in darkness with a sick buddy, ... On a boat dive you have no choice of course, but these guys were still close to the shore and swimming back near the bottom means that at least the victim cannot drop down and always has a visual reference, could even kneel down to fix stuff.

 

[johndiver999]

Consider that the buddy had severe problems of unknown nature and may fail to control his buoyancy during the free ascent, may become negative and fall into darkness. So you may have to take control of his wing and drysuit and rebreather, and yours as well, both of you in rebreathers plus stages, he's on bailout already, you have mandatory deco, floating 100ft above ground in <10ft visibility, no boat, no rope, maybe not even a SMB, in darkness with a sick buddy, ... On a boat dive you have no choice of course, but these guys were still close to the shore and swimming back near the bottom means that at least the victim cannot drop down and always has a visual reference, could even kneel down to fix stuff.

. isn't that EXACTLY the minimum the tech divers would be trained to handle? Is coming up without "a rope" a problem for typical, tech divers? Shouldn't we EXPECT that they can control their buoyancy to some crude extent? What relevance is a boat in this scenario? They can't get on a boat, they have to do deco first. Even the precise control of stop depth is not that critical if the troubled diver is on air.

I just have such a hard time understanding how accruing more deco time and adding narcosis to a distressed buddy is better than just trying to get up to 40 or 50 feet or something.

Perhaps it is semantics? How far is a "close" swim to shore? 30, 100, 500 feet? If it was VERY short distance to the deco bottles and the route was clear, perhaps I might consider not bailing toward the surface.

 

[Dr Simon Mitchell]

Hello,

At the time the buddy disappeared the divers had a virtual ceiling that (based on the profile picture) was around 20m. Therefore, there was no safe path direct to the surface. Thus, the decision was between spending the deco time / staying below the ceiling while ascending in mid water, or swimming back up the slope that they had just swum down. The principle manifestation of difficulty up to the point of the deceased disappearing was fine buoyancy adjustment. I am therefore not surprised in the least that the divers (particularly Diver 1) intuitively gravitated to swimming back up the slope. They had turned and were not continuing the dive as incorrectly insinuated in one of the earlier posts. Yes, of course rebreather divers practice mid-water ascents / shooting a DSMB etc. But it is more difficult on a rebreather than on OC, and with one diver already needing help with buoyancy adjustment I believe they made exactly the right decision (I agree with leadduck).

My own thought processes (as Diver 1) would have been: I'm seeing strange anxious behaviour - triggering event most probably a gas toxicity (hyperoxia, hypoxia, hypercapnia) - my buddy has bailed out - that should control the triggering event - he's obviously rattled and probably not up to the complex process of ascending and stopping mid water - we need to get out of here - lets go back up the slope where we at least have a visual reference and can easily stop to deal with any new problems that arise.

Terribly sad, and I think Diver 1 did pretty much everything right.

Simon

 

[rjack321]

. isn't that EXACTLY the minimum the tech divers would be trained to handle? Is coming up without "a rope" a problem for typical, tech divers? Shouldn't we EXPECT that they can control their buoyancy to some crude extent? What relevance is a boat in this scenario? They can't get on a boat, they have to do deco first. Even the precise control of stop depth is not that critical if the troubled diver is on air.

I just have such a hard time understanding how accruing more deco time and adding narcosis to a distressed buddy is better than just trying to get up to 40 or 50 feet or something.

Perhaps it is semantics? How far is a "close" swim to shore? 30, 100, 500 feet? If it was VERY short distance to the deco bottles and the route was clear, perhaps I might consider not bailing toward the surface.

Controlling 3 sources of buoyancy (wing, drysuit, counterlungs) while also controlling 3 sources of buoyancy in a bailed out buddy is pretty much not going to happen. (even on BO the counterlungs need to be vented). Perhaps with 2 buddies or a mooring/anchor line. Swimming up slope was a wise choice even if it didnt succeed.

Being on air was not helping.

 

[Kay Dee]

First, my condolences to all those directly involved (in all three accidents).

Solo divers do not die. The rebreather and cave divers do.

With all due respect, that is simply either an ignorant uninformed comment or a troll. Divers die in all realms of the 'sport', from the most basic recreational to the most advanced 'technical', and all avenues in-between. (And when all is said and done, we all die.)

With that said;
@Hiszpan, thanks very much for going to the trouble of posting the translation. Nothing like a first hand account to cut through the usual speculation that surrounds most accidents, some of which a cloak of secrecy seems to be hang over, sometimes almost indefinitely unfortunately.

And @johndiver999 (and to a lesser extent @lowwall), given your self admitted lack of knowledge of rebreathers I suggest you take a good hard read and a deep think about all what both Dr Mitchell and @rjack321's had to say in their posts, especially the intricacies / variables involved, as both are experienced rebreather divers.

And given all the intricacies / variables involved, I also agree Diver 1 did the 'right thing'. Unfortunately 'doing the right thing' can still end tragically, but better than two dead divers.

 

[johndiver999]

First, my condolences to all those directly involved (in all three accidents).

With all due respect, that is simply either an ignorant uninformed comment or a troll. Divers die in all realms of the 'sport', from the most basic recreational to the most advanced 'technical', and all avenues in-between. (And when all is said and done, we all die.)

With that said;
@Hiszpan, thanks very much for going to the trouble of posting the translation. Nothing like a first hand account to cut through the usual speculation that surrounds most accidents, some of which a cloak of secrecy seems to be hang over, sometimes almost indefinitely unfortunately.

And @johndiver999 (and to a lesser extent @lowwall), given your self admitted lack of knowledge of rebreathers I suggest you take a good hard read and a deep think about all what both Dr Mitchell and @rjack321's had to say in their posts, especially the intricacies / variables involved, as both are experienced rebreather divers.

And given all the intricacies / variables involved, I also agree Diver 1 did the 'right thing'. Unfortunately 'doing the right thing' can still end tragically, but better than two dead divers.

I appreciate that experienced rebreather divers have taken the time to give an educated perspective.

I'm was initially surprised that losing contact with a distressed buddy (after watching him switch to his bail out and have difficulty working an inflator) would be considered "doing the right thing". I now accept that conclusion from the experts, but initially it sounded like losing contact was a terrible, unfortunate mistake to me.

Perhaps if they share the deceased diver's computer, we would be able to see if he completely lost control of his buoyancy and shot up vertically in bad visibility. That would seem to be an easy way to lose a buddy in limited visibility and could happen in an instant and be very hard to prevent. Perhaps if this did occur it would expand our insight into what happened?

Regardless of the situation, this discussion has been very enlightening to me about how vulnerable and burdened rebreather divers are and just how limited their abilities are to self rescue and/or to provide help to a buddy in a situation where a buddy has switched over to bail out. I honestly never thought that just coming up with one hand on a conscious and ambiguously distressed buddy breathing OC would be so difficult or even impractical. I attribute this entirely to my own ignorance of the specialized gear and the proper procedures involved.

I really do appreciate the efforts to convey this important information to myself and others who may also have very limited understanding of rebreathers.

 

[rjack321]

Regardless of the situation, this discussion has been very enlightening to me about how vulnerable and burdened rebreather divers are and just how limited their abilities are to self rescue and/or to provide help to a buddy in a situation where a buddy has switched over to bail out. I honestly never thought that just coming up with one hand on a conscious and ambiguously distressed buddy breathing OC would be so difficult or even impractical. I attribute this entirely to my own ignorance of the specialized gear and the proper procedures involved.

If they are functioning then yes ascending is often wise. But buddies can be in various states of consciousness and leading someone who's delirious up a slope is inherently easier and safer than a direct ascent even if it takes a few extra minutes.

Maintaining an actual unconscious diver's buoyancy for any length of time is quite challenging. Its part of ever tech course I have taken yet doing stops with an unconscious person is downright perilous.