Scuba diver dies after being found floating at Kurnell, NSW, Australia

[Diver0001]

Just reading back a few posts, some things don't make sense to me but I'm going to throw out a theory to try connecting the dots, at least for myself.

What we know is that Quero had 50 bar in her tank when the descended to swim to shore, which apparently was a short swim in shallow water.

A few minutes later she was found on the bottom with an empty tank and her BCD inflated when only minutes before she had 50 bar and had made a presumably normal ascent and was able to maintain positive buoyancy on the surface.

So what happened in those few minutes that lead to the tank being empty and being negative on the bottom with a full BCD?

So my idea for a scenario is this. This is only my theory. (family please don't read this).

[theory]
At some point while she was separated she ran out of gas, probably due to a free flow given how much gas she had. She had enough time to inflate her BCD and try to swim to the surface (the BCD was inflated). However, the fact that she was found negative on the bottom suggests that she had previously been using both the suit and the BCD for positive buoyancy and she forgot, as in inexperienced drysuit diver, about inflating the suit.

She may have reached the surface while the others were still under water. I'm going to assume she did. She was unable to maintain positive buoyancy because of an unbalanced rig and forgetting about inflating the suit. At that point the tank became empty. It was too late to inflate the suit and it can't be done orally. She struggled, started to get in trouble, stopped thinking straight and to make matters worse failed to dump her weights. She sank and drowned.
[/theory]

If (and that's a big IF) this theory is what happened then it looks like we have a few factors that all conspired to become overwhelming:

- unbalanced rig
- inexperience with the gear
- buddy separation
- freeflow or OOA in some manner
- inability to maintain positive buoyancy on the surface
- not responding by jettisoning weights

Thoughts?

R..

 

[almitywife]

That's if she did have 50 bar. I don't know Quero but I know diver 1 and 2 and they are both excellent on air. If diver #1 had 50 bar as well, my first response was to doubt what Quero said she had.

But this is pure speculation.

 

[Cave Diver]

However, the fact that she was found negative on the bottom suggests that she had previously been using both the suit and the BCD for positive buoyancy and she forgot, as in inexperienced drysuit diver, about inflating the suit.

This was one of my first thoughts as well.

 

[mala]

That's if she did have 50 bar. I don't know Quero but I know diver 1 and 2 and they are both excellent on air. If diver #1 had 50 bar as well, my first response was to doubt what Quero said she had.

But this is pure speculation.

50bar is quite a lot for an experienced diver in shallow water.
the gauge may have been faulty ?
often its a combination of less significant factors including decision making.

respect to the others in the group who from the information available seemed to act in a correct and timely manner.

 

[DevonDiver]

*Not for family*

50bar is quite a lot for an experienced diver in shallow water.
the gauge may have been faulty ?

A gauge can easily be inaccurate at lower pressures. I've got a gauge that reads 20bar when, in fact, you're sucking at nothing. I don't think that such faults are that uncommon (I've seen it a few times). Substantial reserves exist for several reasons - gauge inaccuracy being one of them.

If she got into difficulties (ascent/buoyancy control) with minimal gas, an accelerated (panicked) SAC, coupled with kicking hard to reach/to stay at the surface when substantially negative, could account for complete air depletion in seconds.

If there was a free-flow, a full 50bar escaping from a second-stage should take a minute or two. From what I've read... other divers surfaced in that time. Wouldn't they have noticed the signs of a massive gas loss reaching the surface?

Fully (?) inflated BCD and still negative on the bottom indicates heavy over-weighting. Drysuit can be used as redundant buoyancy, but it shouldn't be used as a critical supplement to BCD buoyancy. BCD alone should always permit positive buoyancy (ascent/surface flotation) to be attained.

It's tragic - but if her weighting had been effective, then a full (really full) BCD should have broken the accident chain - or at least caused her to surface (unconscious) and permitted an emergency response within a potentially life-saving timescale..

I don't like speculation, but another factor not yet (I think) mentioned is a lung over-expansion injury. If she was negative, had fully inflated BCD, and was kicking to the surface - she may have been tempted to breath deep to increase her buoyancy. In a moment of panic, that could potentially turn into a 'breath-hold' ascent. The impact of that would be near-immediate and would result in her sinking back down. Autopsy would confirm or rule-out that possibility (Lung barotrauma signs may not be immediately apparent if recovered, drowned, from the bottom).

 

[AfterDark]

Just reading back a few posts, some things don't make sense to me but I'm going to throw out a theory to try connecting the dots, at least for myself.

What we know is that Quero had 50 bar in her tank when the descended to swim to shore, which apparently was a short swim in shallow water.

A few minutes later she was found on the bottom with an empty tank and her BCD inflated when only minutes before she had 50 bar and had made a presumably normal ascent and was able to maintain positive buoyancy on the surface.

So what happened in those few minutes that lead to the tank being empty and being negative on the bottom with a full BCD?

So my idea for a scenario is this. This is only my theory. (family please don't read this).

[theory]
At some point while she was separated she ran out of gas, probably due to a free flow given how much gas she had. She had enough time to inflate her BCD and try to swim to the surface (the BCD was inflated). However, the fact that she was found negative on the bottom suggests that she had previously been using both the suit and the BCD for positive buoyancy and she forgot, as in inexperienced drysuit diver, about inflating the suit.

She may have reached the surface while the others were still under water. I'm going to assume she did. She was unable to maintain positive buoyancy because of an unbalanced rig and forgetting about inflating the suit. At that point the tank became empty. It was too late to inflate the suit and it can't be done orally. She struggled, started to get in trouble, stopped thinking straight and to make matters worse failed to dump her weights. She sank and drowned.
[/theory]

If (and that's a big IF) this theory is what happened then it looks like we have a few factors that all conspired to become overwhelming:

- unbalanced rig
- inexperience with the gear
- buddy separation
- freeflow or OOA in some manner
- inability to maintain positive buoyancy on the surface
- not responding by jettisoning weights

Thoughts?

R..

I was thinking along those same lines except, perhaps a stuck open inflator drained her tank.

 

[clownfishsydney]

I have now spoken to one person by phone. He was the one who brought her up from the bottom. I have his approval to post what he has told me about the dive and I will, but first I will let him read it and correct any errors. I will say a couple of things now. Her gauge showed 10 bar but the tank was empty. Also, she had about 26 lbs weight using a 10 litre (80 cf) steel tank and trilaminate drysuit. If this is the case, then I believe she was grossly overweighted for someone her size.

Also, I believe that she may have been using an air integrated computer so the air usage will be available to police. However, from personal experience, I doubt they will know what to look for or understand what it is.

 

[DevonDiver]

However, from personal experience, I doubt they will know what to look for or understand what it is.

Does Australia make use of 'expert witness' in inquiries/inquests?

 

[Diver0001]

*not for family*

*Not for family*

A gauge can easily be inaccurate at lower pressures. I've got a gauge that reads 20bar when, in fact, you're sucking at nothing. I don't think that such faults are that uncommon (I've seen it a few times). Substantial reserves exist for several reasons - gauge inaccuracy being one of them.

If she got into difficulties (ascent/buoyancy control) with minimal gas, an accelerated (panicked) SAC, coupled with kicking hard to reach/to stay at the surface when substantially negative, could account for complete air depletion in seconds.

If there was a free-flow, a full 50bar escaping from a second-stage should take a minute or two. From what I've read... other divers surfaced in that time. Wouldn't they have noticed the signs of a massive gas loss reaching the surface?

Fully (?) inflated BCD and still negative on the bottom indicates heavy over-weighting. Drysuit can be used as redundant buoyancy, but it shouldn't be used as a critical supplement to BCD buoyancy. BCD alone should always permit positive buoyancy (ascent/surface flotation) to be attained.

It's tragic - but if her weighting had been effective, then a full (really full) BCD should have broken the accident chain - or at least caused her to surface (unconscious) and permitted an emergency response within a potentially life-saving timescale..

I don't like speculation, but another factor not yet (I think) mentioned is a lung over-expansion injury. If she was negative, had fully inflated BCD, and was kicking to the surface - she may have been tempted to breath deep to increase her buoyancy. In a moment of panic, that could potentially turn into a 'breath-hold' ascent. The impact of that would be near-immediate and would result in her sinking back down. Autopsy would confirm or rule-out that possibility (Lung barotrauma signs may not be immediately apparent if recovered, drowned, from the bottom).

I believe from the little I've heard that the autopsy rules out any obvious things like a lung over expansion injury. However your theory is valid and I think you make a good point (again... seems we're on the same wave-length more than we usually are).

Your other comments are valid. Over weighting, unbalanced rig and the proper usage of a drysuit (a training/technical point) are all valid points. I agree *IF* this theory is true that if she had had a normally balanced rig that inflating the BCD would have cut the accident chain. It seems to suggest a high priority for a balanced rig. That's a clear lesson-learned for everyone.

Other things (again IF my theory is realistic) that could have cut the accident chain are

- not getting separated. Having access to a buddy's air and/or assistance in reaching the surface. As painful is it is, it seems that staying together as a team could have avoided the outcome. It seems that attempts to that end were made but that Marcia herself didn't take it as seriously as could have been. That said, while it may have allowed for mitigation, the root cause is not being separated. Being solo in itself, especially to a highly experienced diver and in 3 meters of water isn't directly life threatening. Perhaps risks are somewhat increased but not to the point that I would describe it as a cause.

- not getting OOA. It's unclear if she could have controlled being OOA or not. There seems to be two possibilities here. Either (a) there was an equipment malfunction that caused a free flow or (b) she went OOA without an equipment malfunction. In either case I would describe this as a trigger. However, in normal circumstances -- regardless of the cause -- she would have just swam to the surface. My reading (personal opinion) is that if she *hadn't* been using new gear that she wasn't familiar with that going OOA would have been an inconvenience at that depth. The combination of OOA and the new gear seems to have created a severe complication.

R..

 

[Zippsy]

Some people are using the term "balanced rig". I know what that means when I am using it in reference to wetsuit / tropical diving but I suspect it means something different here with a drysuit. I could guess but I would appreciate hearing your definition. Thanks.