Fatal dive accident - Lake Werbellin, Germany

[dmaziuk]

Apologies in advance for my ignorance, but can I ask what are the precise circumstances about the incident that are leading to the hypothesis of Co2 poisoning?

2 instructors, open water dive to 38 m, came up to 6 m, spent 20 minutes there before running out of gas. The only way I'm not swimming up from 6 m is if I'm unconscious or tied to the bottom; two experienced divers simultaneously running OOG and not swimming up from 6 m is... very strange.

PS. of all the things that could render two divers unconscious at once on (what sounds like) an otherwise fairly benign dive, bad gas just about tops the list.

 

[cathal]

came up to 6 m, spent 20 minutes there before running out of gas.

PS. of all the things that could render two divers unconscious at once on (what sounds like) an otherwise fairly benign dive, bad gas just about tops the list.

Do you mind explaining how we know two instructors spent 20 minutes at 6M before running out of gas? Its an important piece of information, thanks.

 

[cathal]

I would hope not. Yes, there is a lot of speculation here, but that's how we learn to minimize risks when the facts are not forthcoming. Until we do know, CO is certainly a possible risk here as it does fit the incident.

I'm sure we all agree educated speculation by competent persons, otherwise known as 'guestimating' in other parts, can be quite accurate. However, with this incident there is a dearth of information, just a media report. Speculation based on a media report is simply not accident analysis. By all means continue to speculate about Co2, but split the thread in that event, so that this thread remains about the actual triggering events and cause of death.

 

[Robbyg]

It looks like this accident is not related to CO poisoning. It has been written somewhere, that both had empty tanks.

I am certainly no expert but it's hard to believe that they don't know if it's CO.
An empty tanks as far as being able to breathe air is concerned, I can understand.
An empty tanks as far as getting a Lab Air Sample seems really far fetched. Even if I held my regulator up towards the surface at 20M and purged the Tank to Zero there is no way the Tank can fill up completely with water. Worst case there is air trapped at the top of the Tank below the siphon pipe on the K valve. I would think that any lab worth their salt would carefully extract any air left and do tests on it. Personally I kind of doubt the tank would have filled with water as it's unlikely you could suck out those last few PSI of remaining air.
I know CO2 in a tank can dissolve into any water in the tank but I don't know if CO is the same.

If there is a flaw in my thinking I would love to know what it is.

 

[Joris Vd]

I read on a german dive forum from someone who claims to have been there that the buddy pair both dove 7x2l. iN 39 F water, with a max depth of 39 meters (127 feet) if you have a freeflow or any issue, you'll be burning through the safety margin you have with a small set like that real fast. But then again, we can speculate all we want, so far there's not much to know sadly...

 

[Nirvana]

I am in agreement with @cathal above as not seeing the point in getting too attached to the carbon monoxide theory. The empty tanks are too thin a link to CO as a cause of death to warrant, at this point, a long discussion of the danger of this gas in this thread.

By the way, I know of at least one incident in which an open water instructor died, out of air, swimming in shallow water, with no CO involved.

 

[dmaziuk]

Do you mind explaining how we know two instructors spent 20 minutes at 6M before running out of gas? Its an important piece of information, thanks.

"We" read it in posts #1 and #6 of this thread.

 

[DandyDon]

Do you mind explaining how we know two instructors spent 20 minutes at 6M before running out of gas? Its an important piece of information, thanks.

It's difficult to know much from limited sources, but we're discussing that based on these two posts on page 1...

Two dive instructors had a fatal accident last Sunday while diving in lake Werbellin.
Both divers were found in 6 m depth and were brought to the surface.
According to the dive computers they were at max. 38 m and spent approx. 20 minutes at 6 m depth, when they were found.
Resuscitation was unsuccessful and both died.

On the german taucher.net board someone mentioned, that both were OOA.

Dying OOA in 6m depth is really strange.
I hope we can get more details on this one

By all means continue to speculate about Co2

I don't think anyone here is going to speculate Carbon Dioxide as it's generally not an issue as long as there is enough Oxygen in the mix.

split the thread in that event, so that this thread remains about the actual triggering events and cause of death.

Do you know what those triggers were? It's difficult to imagine two instructors drowning from OOA at 6 meters. CESAs are too easy. I survived one from 15 meters once after a dumb mistake with enough found air to take a breath on the way and inflate my BC. The best we can do for now is speculate about triggers and responses or lack thereof, and CO just seems the most likely cause. Why are you so defensive about that risk?

I know of at least one incident in which an open water instructor died, out of air, swimming in shallow water, with no CO involved.

Oh, was his tank tested before or after? How can an instructor fail a shallow CESA?

 

[scubaozy]

I did not read anything indicating that divers reached 6m alive and were conscious all that 20minutes. I would first assume a free flow and OOA if the tanks were empty, because that was one of the coldest days in several years. If they were not conscious at 6m it should be possible to see it from their dive computers as the recorded depth would be variable if they were conscious. If their tanks were empty, most probable trigger for incident is out of air and their reaction to this trigger.
If divers had variable depth recorded by their dive computers at 6m at least for a while, I would suspect CO in the tank which should be possible to test from the remaining tank content if any left.

 

[John the Pom]

As a young engineering student living in dismal housing in northern England, one of my friends suffered mild CO poisoning from a faulty gas heater. She experienced extreme disorientation and vivid, frightening hallucinations - not symptoms I've heard discussed with reference to CO.