Rob Davie's accident. (aka. BigJetDiver)

[Kim]

As most people know Rob Davie (BigJetDriver) died recently during a rebreather dive in the Red Sea. This thread is to discuss that accident.
The main factual information concerning Rob's accident has been posted by drmike on rebreatherworld.com. I am assured that these facts are 100% accurate. It is reproduced here with permission.

I was the only diver left on the boat when Rob surfaced
From his comp - Dive time 4 mins
max depth 80 feet
Afterwards buddy said he saw him bail to OC on descent at around 70-80 feet and ascend to surface
Buddy saw him surface and swim towards boat.
He was seen by crew just under the surface unresponsive
We send out a zodiac and dragged him on board and brought him back to boat
we tried cpr but he was gone, no pulse not breathing
his unit;
110 bar left in air dil
160 bar O2
Unit turned off (conducive with bailing)
Mouthpiece could not close due to miss aligned center screw.
Mouthpiece had foreign object inserted into it (for some reason)
it reduced internal bore dia. considerably
Screws that secure both hose colars to mouthpiece missing so could not open/close mouthpiece correctly.
Added:
Unit later shown to have flooded (but as he couldnt close the mouthpiece it could have flooded during ascent after bailing)
All 3 cells were 18 months old - from the same batch (not thought to be relevant given the dive time was only 4mins)

Previous dive he had mentioned he had problems with his mouthpiece but told crew he had fixed it prior to last dive.

Some more information:
His 5ltr bailout cylinder still contained air. (the exact amount is still being confirmed but was thought to be around 150 bar, about 26.5 cu/ft)
What gas was left in the loop (very little) was analyzed and found to be good.
The volume of the counter lungs was 14ltrs - so by adding the volume of the hoses and the scrubber it is possible to realize that the weight swing due to the flooding of these spaces could have been in excess of 14kgs maybe as much as 17/18kgs.
Full specifications of the Inspiration rebreather can be found here:
A fuller discussion as to the possible weight swing caused by a flooded rebreather can be found here.
I have inquired, but it isn't known, how much lift his Oxycheck wing gave. In the technical specification link above though the maximum wing lift sold actually with the unit is 22.5kgs.
His wing was completely full when he was found just under the surface.
No ditchable weight was found still with him, but it is also not known yet what amount he normally used - if any - so precisely how buoyant or not he would have been.
I imagine that some questions may arise about his buddy. Before anyone is quick to assign blame in that direction this thread may address some of the factors that should probably be born in mind.
While some speculation is inevitable in such a discussion, please keep it within the bounds of the known facts. As always the special rules of this forum will be applied. Further - please be aware that there is a very good chance that the exact cause may never be established for certain. Let's not try to convert 'best guess' into 'truth'.

 

[wedivebc]

Thank you Kim for posting this. I know many, out of respect for Rob kept speculation to a minimum but nature abhors a vacuum and the information will flow. It might as well be based on facts.

Unit turned off (conducive with bailing)

This is not how I was taught but others may do things differently

 

[cool_hardware52]

No ditchable weight was found still with him, but it is also not known yet what amount he normally used - if any - so precisely how buoyant or not he would have been.

I have no knowledge of Rob's actual configuration when he had his accident. I do know Rob routinely used and recommended a commercially available "Weight and Trim" harness.

He told me he preferred this harness specifically because he need to carry substantial weight with his RB. This stands to reason if you have a machine with internal volume of 14 or more liters.

Is it known if he was wearing a weight harness?

Tobin

 

[wedivebc]

I am curious why all the concern about weight and flooded loop buoyancy. If he was at the surface wouldn't you surmise that was not an issue?

 

[Kim]

Is it known if he was wearing a weight harness?

I don't know that for sure - I'll try to find out. It IS known that he was not wearing any weights that he could still have ditched. I don't know exactly how weights in a harness work.....are they ditchable?

 

[Kim]

I am curious why all the concern about weight and flooded loop buoyancy. If he was at the surface wouldn't you surmise that was not an issue?

For me it could be important as it could indicate some buoyancy issues at the surface. As he was found "just under the surface unresponsive", but with a fully inflated wing it's actually quite hard to picture. I would expect someone to be positively buoyant and therefore at the surface, or negatively buoyant therefore sinking. "just under" seems odd. Maybe someone else can explain how that could happen

 

[cool_hardware52]

I don't know that for sure - I'll try to find out. It IS known that he was not wearing any weights that he could still have ditched. I don't know exactly how weights in a harness work.....are they ditchable?

Yes they are ditchable, the harnesses function quite like a weight integrated bc, but there's no BC, just suspenders, a belt and pockets that accept ditchable pouches.

These are popular with divers that carry a lot of weight because you can don them first, and out of the water the load is carried on the shoulders and not the hips.


Tobin

 

[Kim]

Yes they are ditchable, the harnesses function quite like a weight integrated bc, but there's no BC, just suspenders, a belt and pockets that accept ditchable pouches.

In that event it doesn't really matter if he was wearing a harness or not as no weights were found in it.

 

[Darnold9999]

If he was wearing such a harness he would still be wearing it if he ditched weights. A lot of us that dive dry wear such harnesses for exactly the reason given. Moves the weight to the shoulders and allow you to don it separately. If the harness was on and the weights gone it would indicate a serious problem with boyancy.

 

[cool_hardware52]

If the harness was on and the weights gone it would indicate a serious problem with boyancy.

That's exactly my thought.


Tobin