FP triple fatality

[KevinNM]

There was a multi page article in GUEs Quest on GUE in Frances year or so ago and it was kind of complex. The whole permit system, etc. It is not like US diving.

 

[Darghu]

There was a multi page article in GUEs Quest on GUE in Frances year or so ago and it was kind of complex. The whole permit system, etc. It is not like US diving.

Mind to share which Quest, if you remember, please ?
You are referring to BPJEPS ?

 

[KevinNM]

Mind to share which Quest, if you remember, please ?
You are referring to BPJEPS ?

16.1

 

[Freewillow]

Some instructors suggest to take a Nitrox course just after Level 1. So some divers are certified Nitrox and will prefer to dive with LDS who have Nitrox fills. But more infos are needed here and I guess we will not know what happened into this incident.

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I do not understand why Nitrox would help in this situation. Air @ 60 meters gives you a PPO2 of 1,47. No need to add oxygen toxicity to narcosis .

While I dived only once @ 55 m on air -Roraima wreck in Martinique -I know quite a few european divers that have done it regularly @ 60 m on air with a single cylinder. They all are experienced and say - pretend - that they can feel when they are getting too narcosed. They always go together and have one rule. Everyone has the right to tumb the dive when too strong narcosis starts.

I do not totally agree with this but where I disagree totally is the idea of any penetration - wreck or cave - @ 60 m on air

 

[dmaziuk]

Preliminary Opinion: this should have been strictly an open water multi-level deep dive. Given the assumption of single tank backmount usage only, no more than five minutes bottom time is warranted to look at the entrance of the cave at 60m before starting a multi-level ascent profile as determined by dive computer and usable remaining breathing gas volume. It was either a naive but tragic unfortunate misadventure -or gross fatal mistake of judgment- to even attempt to enter the cave at that depth.

Not that I looked very closely, but from some Russian chatter out there I get the impression he was one those guys who wouldn't walk past a mountain without climbing it "because it's there".

 

[Bob DBF]

They all are experienced and say - pretend - that they can feel when they are getting too narcosed.

If they were trained properly, I would believe them. Before the advent of Nitrox and trimix, we were trained on air and did all diving on air, you learned to deal with narcosis or stayed shallow. One can learn to evaluate ones impairment and ability to deal with the impairment and dive or thumb the dive.

The larger problem with narcosis is divers now having no idea how to gauge their imparment and believe they are not narked at all. It is fine until there is an emergency and they find they can not properly respond because they are narked.



Bob

 

[Kevrumbo]

If they were trained properly, I would believe them. Before the advent of Nitrox and trimix, we were trained on air and did all diving on air, you learned to deal with narcosis or stayed shallow. One can learn to evaluate ones impairment and ability to deal with the impairment and dive or thumb the dive.

The larger problem with narcosis is divers now having no idea how to gauge their imparment and believe they are not narked at all. It is fine until there is an emergency and they find they can not properly respond because they are narked.

Bob

A 60m (200ft) dive on air. . . I believe we are way beyond safe recreational diving here, and I doubt most tech divers are not going to do that on air.

I do not understand why Nitrox would help in this situation. Air @ 60 meters gives you a PPO2 of 1,47. No need to add oxygen toxicity to narcosis .

While I dived only once @ 55 m on air -Roraima wreck in Martinique -I know quite a few european divers that have done it regularly @ 60 m on air with a single cylinder. They all are experienced and say - pretend - that they can feel when they are getting too narcosed. They always go together and have one rule. Everyone has the right to tumb the dive when too strong narcosis starts.

I do not totally agree with this but where I disagree totally is the idea of any penetration - wreck or cave - @ 60 m on air

The three teammates should have all had at least an Alu 11L twinset (AL80's) and a single 11L stage cylinder, and deco bottles of Eanx50 and O2. Bottom Time depending on sizes of the deco bottles can range from 30 to 50min, assuming a Sac Rate of 12 to 15l/min nominal.

Air at 60m (7ata) has a gas density of over 8 grams/liter. If you're expecting heavy breathing due to physical exertion at that depth you should be using a DPV/Scooter and/or a bottom mix no greater than 6 g/l. Ideally this should be a lot less for better margin against Work-of-Breathing CO2 retention/Hypercapnia at deep depth (18/45 Trimix has 5 g/l gas density; but 20/20 "Economy Tropical Trimix" has 6.6 g/l). Unfortunately for open circuit diving, an Alu 11L twinset with 20/20 "Economy Trimix" costs $200, and 18/45 costs $422 ($1 per 28 liters/1cuft of O2, and $5.75 per 28 liters/1cuft of Helium, current Micronesia Truk Lagoon gas costs).

For a wreck penetration, a single 11L Stage Cylinder at 60m will last me 20min with nominal activity before emptying it (breathing rate of 10bar/min at 7ata depth); tactically I would breath less than half than this -7 min- and drop/clip it to the penetration line I'm running inside the overhead, switch to backmount twinset 11L Cylinders (breathing rate of 5bar/min or a little better), and run some more line out and/or look around for another 8 to 10min, or until reaching a Third's turn pressure of 155bar actual SPG reading. Turn around, reel line in and pick-up the stage cylinder, and breath it on the way out. Total time inside the overhead at 60m will range from 15 to 25min at best.

The point is your buddy has additional gas in his twins if you have a out-of-gas contingency at your furthest penetration because of reserving an additional third's volume equivalent of the single 11L stage in his twins. You swim back sharing air to each of your individual stage tanks. Your buddy's back gas is not threatening to run out at any moment, and you are in much better shape gas wise in a team of three, as you arrive back at your own stage tank. Here you each collect your respective stages and commence breathing them back to the overhead's entrance/exit opening into open water. Your other buddy then shares gas with you as needed to reach the 21m deco stop and switch to Eanx50.

(See: http://www.funteqdiving.nl/website/Downloads/duikplanning/Trewavas - Rethinking Thirds.pdf )

Again, if the team was not trained in all the above overhead diving techniques and deco procedures, then what a tragic, unfortunate and sad misadventure. If they were trained and knew better -what a gross unforgiving and fatal mistake. . .

 

[NYCNaiad]

My friend is friends with a colleague of the Russian man & woman who died. My friend actually brought the story to my attention before I saw it here. He said they were both adrenaline junkies pushing the limits with a lot of things they did. I have no idea what the cause of the accident was, but when I hear something like that, it makes me wonder whether pushing the limits played into the cause.

Sad either way & my heart goes out to their family & the family of the guide.

 

[dmaziuk]

He said they were both adrenaline junkies pushing the limits with a lot of things they did. I have no idea what the cause of the accident was...

Yes, that's the impression I get from the Russian-language comments, too. It looks like the cause is pretty much what Kev says: with a single 100cf tank at that depth it's enough to kick up a bit of silt and let go of the line.