Filmmaker Rob Stewart dies off Alligator Reef

[Dsix36]

Years if experience and muscle memory can still screw you if you have any new equipment that is different. When I finally trained on a rebreather with a BOV (never used one before) I proved it to myself that a BOV and DSV have different protocols. Muscle memory and training resulted in mistakes and partially flooding more than once, even after class.

 

[Capt Tom McCarthy]

Not since you "ripped" me for the last one! Like I posted earlier, you made it a "teachable moment" and it didn't leave a bad taste in my mouth. As penance, I have created the following meme:

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I laughed too hard at these. It's refreshing to see someone happily admit when they were wrong without making a big thing out of it! We're all here to keep learning at the end of the day.

 

[MarkFlory]

Even the most experienced CCR diver being in this stressful situation watching Peter struggle to get up the ladder ( allegedly ) could have easily made a mistake as simple taking the DSV out of his mouth and forgetting to close it to ask if his buddy was ok. In a minute or two that rEvo could have turned as heavy as a boat anchor.
"The Chain of Events That Causes Accidents”

 

[crabbyfiddler]

In case it's of interest, here's a pilot of a freighter in distress at about 18,000, which is a PP02 of about 0.10 or so.

Sounds like he's drunk, right?

Hypoxia is pleasant.

That was really nerve wracking to listen to. Kudos to pilot.

 

[The Chairman]

We're all here to keep learning at the end of the day.

This bears repeating. This bears repeating.

Many seek to prove themselves right. I seek to find out what's right.

 

[dumpsterDiver]

Does the victim's BC have sufficient capacity to offset a fully flooded Rebreather? Is this something that is considered when selecting components? If not why not?

 

[Wookie]

Does the victim's BC have sufficient capacity to offset a fully flooded Rebreather? Is this something that is considered when selecting components? If not why not?

I am completely unqualified to comment here, so here I go.

A rEvo is extremely heavy, designed for diving in cold water in the North Sea. One way to combat this is to put the hoop wrapped cylinders on it, except they aren't legal to fill in the US and transport on an inspected dive boat. It's heavy because the divers are expected to be wearing drysuits, which Rob reportedly was. Remember, a BC is not a lift bag, it is designed to compensate for changing buoyancy as you use up your cylinder. But in my limited experience, all rebreathers are negative, and filling the counterlung makes them closer to neutral. Which is the discussion here. Spit your mouthpiece, the breathing gas is forced from the counterlung, and if the drysuit and BC aren't full, the diver may sink.

It's tough and IMO unnecessary to make something to do with diving inherently safe. Diving is not inherently safe. It has inherent risks. We mitigate them with training.

 

[The Chairman]

to offset a fully flooded Rebreather?

It doesn't have to flood to get negative. The pressure of the water can completely deflate the counterlung so that it's simply empty albeit not full of water.

As for buoyancy, with AL19s my SF2 seems to be barely negative in fresh with min loop volume. I want to see how she is in salt, but I have a sinus infection to get over first.

 

[Brad_Horn]

Does the victim's BC have sufficient capacity to offset a fully flooded Rebreather? Is this something that is considered when selecting components? If not why not?

The rEvo has a CE mark so theoretically the supplied BCD meets EN 1809 BS EN 1809:2014+A1:2016 - Diving equipment. Buoyancy compensators. Functional and safety requirements, test methods and has been tested to ensure it provides sufficient buoyancy for the unit and diver.
That the supplied BCD is fit for purpose on the unit is required for a rebreather's EN 14143 certification. You cannot recover from a flood on a rEvo, so that is apparently a normal mode for it, and you would expect it was considered in the design of the BCD...

But then the rEvo does not meet either EN 14143 standard, be it :2003 or :2013, so who knows.
It would also depend on what BCD the unit dived, was fitted with, as it could have been an aftermarket choice; not designed for use on an rEvo.

It's tough and IMO unnecessary to make something to do with diving inherently safe. Diving is not inherently safe. It has inherent risks. We mitigate them with training.

ALARP ALARP - Wikipedia is perhaps a better consideration than unnecessary....
If you engineer out as many risks as possible first, you minimise the need to mitigate poor design choices later. Adding a safety buffer for the diver!

 

[dumpsterDiver]

Man, you guys use a lot of big words. It just seems like.. if the rebreather failed and flooded etc. (at depth or on the surface) a diver would go to an open circuit bail out and it would make little sense not to be able to get off the bottom, (or stay on the surface) should the worst occur.

So Pete's premise, if I understand it, is he flooded his unit and sunk. Would not a highly experienced tech diver press the "up" button on his BC as he started to sink? Seems like that would be recoverable.