UK wreck death

From Divernet:

DIVER LOST AFTER 55M WRECK DIVE
A man in his 30's was reported missing on Sunday 23 March after diving on the wreck of the Medoc out of Plymouth.
Charter boat Cee King contacted Brixham coastguard and reported Patrick Bumphrey, a Bristol-based solicitor, missing after his buddy surfaced in distress. Bumphrey appears to have been using mixed gas to dive the 55m wreck and had reportedly switched onto 100% oxygen for his final decompression stop when he was seen to convulse and sink rapidly.
The diver and his buddy had initially returned to the shotline with the rest of the group, but following instructions given in the dive briefing by the skipper, had then bagged off and were decompressing on surface marker buoys when the incident occured. Local dive boats and clubs joined in the search for the lost diver while his buddy was taken to DDRC.
The fatality is the first UK diving death of 2003.
25 March 2003

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The original reference I saw had mentioned oxygen toxicity as probable cause. The rapid sinking in open water is somewhat disconcerting.

Always takes one aback to read that sort of news but thanks for posting it matey.

Without more complete information -- about the dive profile and about the physical condition of the missing diver -- it's tough to pin down with certainty what happened, but an OxTox episode would certainly be a candidate.

Take care

DD

Scubaroo once bubbled...
The rapid sinking in open water is somewhat disconcerting.

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I agree. A neutrally bouyant diver wouldn't sink rapidly... end dive... shallow water. Right?

KeyLargoBrent once bubbled...


I agree. A neutrally bouyant diver wouldn't sink rapidly... end dive... shallow water. Right?

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Hi Brent:

surprising how many incidents of toxed divers or unconscious divers begin -- and too often end -- with the stricken diver sinking. I think it's a function of passing out with less than "normal" vital volume... and perhaps also relaxing suddenly... time to do some experiements in the water this weekend!

Black Humor
A buddy of mine always clipped himself to the line -- or a rock -- during long decompressions. Asked why he'd reply: "So I don't sink too far or bob to the surface if I pass out." Sage advice perhaps.

Take care

DD

Black Humor
A buddy of mine always clipped himself to the line -- or a rock -- during long decompressions. Asked why he'd reply: "So I don't sink too far or bob to the surface if I pass out." Sage advice perhaps.

Take care

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I have been told by a couple of extremely experienced Mid-Atlantic wreck guys that this is precisely the reason they use a jonline and clip it to their harnesses during deco. Their thoughts were that if you are going to tox at your 20' stop that they would rather be tethered to the line where their buddy could get to them than blown off in current and possibly sink to the bottom.

Doppler once bubbled...
A buddy of mine always clipped himself to the line -- or a rock

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Sounds like a good idea... I think I'll rig a jonline. Any thoughts/advice?

P.S. Let us know how the "experiments" turn out.

How much water would such a drowning victim take in and could this possibly be the cause of the quick shift to negative buoyancy?

This past weekend, I attempted to simulate the events that one might imagine would take place when a decompressing diver suddenly passes out... do they sink, do they float?

Methodology was pretty straightforward. I would get horizontal and neutrally buoyant holding a "skydiver" position for at least 30 seconds breathing normally. Once I was sure that my inwater attitude was completely stable, I would exhale slightly, halt my breathing cycle and go limp. There was no way to simulate taking a lungful of water... not that was safe! So this was not done.

The conditions were pretty typical of the Great Lakes in April... cold. Water temperature was about 3.5 degrees (38 F). No current and no wind. I was in 65 feet of water within sight of a shot line which itself was marked at intervals with loops and clothes pins (I was conducting buoyancy skills classes for some deco students).

I tried the exercise at 20 feet and 40 feet, and I repeated it at each depth twice with the same outcome.

The results were, as you might expect, that I sank. Interestingly to me at least is that three of the four times my in water attitude did not stray from horizontal but once it changed to slightly head down. Speed of my descent was slow at first but quite definitely negative.

Not sure if this proves anything at all, but certainly if water were to replace air in the breathing pathway and or lungs, the net effect would be more dramatic since a litre of water weighs a kilo (well slightly more with all the crap in it).

One thing it has reinforced in my mind... long decos on a line will see me always deploying a Jon line.

Take care

Doppler,
Thanks for doing some informal trials. I think that confirms what most of us thought - if you lose it at deco you will probably sink, which makes sense since one would maintain neutral buoyancy at stops and would then cease breathing (like you tested) and possibly have the lungs fill with water (resulting in increased negative buoyancy).

Unless someone can point out a damn good reason for not using a jonline, I think I may be with you on that.

After reading doppler's experimental study, if I ever venture into deco diving, I believe a jonline would be with me on every dive I made...it just seems to make common sense.