Virginian diver dead at 190 feet - Roaring River State Park, Missouri

[Nitrogenius]

Honestly I really do not see a lot of merit discussing why the gas was 26/0 and labeled 24/0..
that is such a minor and hence irrelevant factor here. Certainly an indicator on the overall scrutiny to the overall approach to this endeavour, but not even a real contributing factor in the merit.
The real topic should be how does a "surface manager" and support diver on such a frontier setting project get to take a hyperoxic gas as sole bailouts on a planned 195 ft dive and apparently thinks this is ok to do and thinks usage of such gas has any merit to it?
The NSS report already states that the MOD was violated for BO purposes resulting in a massive disregard of best practises for Dil planning from both gas density and diluting capacity aspects.
The lack of Helium aside (which presence would have helped impairment, gas density and decompression schedule) in no scenario does a 24/26 % bailout or diluent make any sense over simple air (which would still be a very poor and questionable choice). The accelaration of decompression is neglibile and the diluting capacities are reduced.
So how does one get there?
To me that seems to imply a serious lack of understanding (/training?) of properly executing dives with the equipment involved and to such depths.
Given the above, how does such diver become surface manager and/or support diver of such an expedition/project?
It is mind-boggling to me!
Also to read that the two BO tanks (that on top of that were being used for DIl purposes) were 50cft tanks only is beyond comprehension!
How are the undoubtedly way more experienced "push divers" ok with their support crew using such setup?
Were they all using such small tanks due to the restriction(s) and the actual BO plan alwys involved use of staged tanks?

As stated before I am really puzzeled by this accident but also what apparently precedented it and it is hard to even start where this whole setup deviates from applicable standards. Best practises in an expedition team setup not even to mention.
This all reads sooo off for the 2020s and even in the 80s/90s this would have been questionable but a little more comprehensible given available ressources/ experience of the industry etc. how one could get there..

 

[Nitrogenius]

"I'm going to do a 130 foot dive to stage some bottles. I'll use EAN24 for that. It's not deep enough to need helium." He prepared his cylinders and his computers based on that.

Just that also for a 130 foot dive an EAN 24 as BO is a poor choice and as DIL even more poor. It makes no sense to use anything lower than a EAN 28 for BO purposes over air.
It makes no sense to use any EAN as Dil over Air.
I can see if you use BO also for Dil why one would potentially plug an EAN28..
Having said that though any non Helium mix seems to be a poor choice in the circumstances especially in an OHE, but using EAN 28 or EAN 32 without He content has some merit in some practical considerations and setups.
Having no He in Dil really only makes sense on very very shallo wdives, but that is one of the disadvantages of using BO for Dil.

i doubt this is an accurate account, according to the report the dive plan was established from the get go
you dont ad hoc a dive if your supposed to be acting as safety diver for divers 1 and 2 that were going to 225' and possibly 300'.

Don't really matter gas choice is beyond poor no matter what..

Just sad especially as it seems to have been so easily avoidable just following established rules and practises, so good reminder why they are in place overall..

 

[Whitrzac]

They likely started out as 32% fills from a cave country trip and were topped with air a few times. It would also account for the slight variance in analyzed/marked vs actual(topped with air and checked before they cooled)


50s were more than enough gas, I believe it was mentioned that they were at most 50ft from the next stage bottle. One of the news articles mentioned 10-14 stages.

 

[Tracy]

Also to read that the two BO tanks (that on top of that were being used for DIl purposes) were 50cft tanks only is beyond comprehension!
How are the undoubtedly way more experienced "push divers" ok with their support crew using such setup?
Were they all using such small tanks due to the restriction(s) and the actual BO plan alwys involved use of staged tanks?

The American way of describing tanks makes things blurry.
Does it help if they are called 7L tanks instead of 50s?
They were most likely filled to 3600-3900 making them 70 some CF. Pretty similar volume to an AL80 which is a standard deep BO for that depth range.

 

[L13]

The American way of describing tanks makes things blurry.
Does it help if they are called 7L tanks instead of 50s?
They were most likely filled to 3600-3900 making them 70 some CF. Pretty similar volume to an AL80 which is a standard deep BO for that depth range.

I would switch to metric diving in a heartbeat if I could get my buddies to go along!

 

[grantctobin]

I would switch to metric diving in a heartbeat if I could get my buddies to go along!

Just keep bottle marking consistent with whatever is more common in the area

 

[Tracy]

Just keep bottle marking consistent with whatever is more common in the area

Yep. It is annoying but you have to remember who the MOD stickers are for.
My computer is in meters. My gauges are in bar, and my mod stickers are in feet.

 

[Manatee Diver]

Yep. It is annoying but you have to remember who the MOD stickers are for.

For me it is for both myself and my team.

 

[Tracy]

For me it is for both myself and my team.

Same here, and most everybody in the water with me is in feet. I can switch back and forth pretty effortlessly at this point.

 

[John the Pom]

I promise you, you will gain far more respect by calling attention to a problem than you would by hiding it.

You will 100% absolutely be blackballed forever from just about any respectable project if you are dishonest and/or willingly violate standards and procedures.

That's exactly what "good safety culture" is all about. Non-dive related, but my work colleague called a halt to a multi-$100M project because a contractor was breaching HSE protocols. He was backed-up fully by senior management, which is the way it should be (but often isn't).