Error Blue hole fatality

[divezonescuba]

Just came back from Dahab and based on what my (Tech/CC) guide said:
-It was a Tech OC dive to 60m
-There was 1 guide (victim) and 9(!) divers
-General setup was twinset (unsure what gas) + 2 stages - 1 with Air, 1 with 50%
-Plan was to descend on the stage with Air, however it seems that instead 50% was used, which has resulted in convulsions (hyperoxia) once he has reached deeper regions

Thanks for posting.

If it was 60m, they were most likely planning on going thru the arch. This new information generates additional questions.

For a 60m arch dive, we would have used x18/30 as the backgas and either x32 or x50 as the low o2 deco gas, and x100 as the high o2 deco gas. Many guides use x32 as a travel gas on the way down and as a deco gas up to conserve He. We switch at 100 ft (30m) when we do that.

If they had access to x50, they would have had access to x100. If they carried two stage/travel gas/deco cylinders why would they not carry x100 in one of the two tanks.

I have been told that some guides will do the arch on x21 as the very top of the bottom of the arch is still around the TDI x21 1.4 gas limits. Those same people commonly use x50 as a single deco tank gas. That configuration is not unusual for doing the Canyon.

However, it does not make much sense to use x21 as a travel gas if you are only planning on going to 60m and are using some blend of trimix such as x18/30.

On the other hand if they did use x21 as the bottom gas, it seems equally strange that an addition cylinder of x21 was used as a travel gas for a 60m dive.

So more questions remain to be answered.

 

[makar0n]

As I understand this, it means the problem actually took place on the surface, when the victim started breathing from the wrong tank at the very start of the dive.

Thanks for posting.

If it was 60m, they were most likely planning on going thru the arch. This new information generates additional questions.

For a 60m arch dive, we would have used x18/30 as the backgas and either x32 or x50 as the low o2 deco gas, and x100 as the high o2 deco gas. Many guides use x32 as a travel gas on the way down and as a deco gas up to conserve He. We switch at 100 ft (30m) when we do that.

If they had access to x50, they would have had access to x100. If they carried two stage/travel gas/deco cylinders why would they not carry x100 in one of the two tanks.

I have been told that some guides will do the arch on x21 as the very top of the bottom of the arch is still around the TDI x21 1.4 gas limits. Those same people commonly use x50 as a single deco tank gas. That configuration is not unusual for doing the Canyon.

However, it does not make much sense to use x21 as a travel gas if you are only planning on going to 60m and are using some blend of trimix such as x18/30.

On the other hand if they did use x21 as the bottom gas, it seems equally strange that an addition cylinder of x21 was used as a travel gas for a 60m dive.

So more questions remain to be answered.

That is all I have heard from the guide, do not have any more details sadly.
What stands out for me is the 9:1 ratio....That is a bit much even for a recreational dive, and could suggest "tech" (quotes intended) divers trying to do arch on the cheap or with a "hold my beer" approach, perhaps cutting corners here and there gas wise. Such amount of divers could also contribute to a general chaos a the beginning of the dive, which in turn could lead to a mistake like breathing from a wrong cylinder.

 

[divezonescuba]

Yes. I don’t think a dive guide is even allowed by cdws to have that many in a recreational shore or safari dive?

It does sound like one of those “unsanctioned” dives that no cdws approved technical dive center would allow.

Because of the limited entry space and the snorkelers in the main area, it had to have been a total cluster.

That instructor was also renewed, but out of teaching status from the PADI web site.

 

[divezonescuba]

Just came back from Dahab and based on what my (Tech/CC) guide said:
-It was a Tech OC dive to 60m
-There was 1 guide (victim) and 9(!) divers
-General setup was twinset (unsure what gas) + 2 stages - 1 with Air, 1 with 50%
-Plan was to descend on the stage with Air, however it seems that instead 50% was used, which has resulted in convulsions (hyperoxia) once he has reached deeper regions

I just noticed some more details in my inbox, I forgot to post it at the time. I am going to do that now, just for the sake of making the thread complete.

An instructor down there looked into this situation for me. He positively stated that the individual was diving sidemount at the time of the accident. That individual was actually one of two people that died in separate incidents at the Blue Hole around that time. The second incident also involved a bad gas switch at depth. Some people may be confusing the two.

So, this means that there is conflicting information as to whether the original indivdiual Mr. Essam was diving backmount twinset or sidemount.

So, my current thinking is that Mr. Essam not only did a bad gas switch which was not noticed by the other divers in the group, but that he may have also had his gear configured incorrectly which facilitated the problem. In the Golden Boy video at the Blue Hole, the divers gear is configured / used incorrectly.

Lastly, a lot of people on the board denigrate the use of color indicating hoses and the like. However, if Mr. Essam was using a yellow hose for 50%, at 60 meters, it would have been a lot easier for any of his 9 fellow divers to realize that there was an issue.

Here is the golden boy video.

 

[John C. Ratliff]

I have read through this thread, and it reinforces my decision to never do technical diving. Why? Well, I’m a retired safety and health professional, and industrial hygienist. I have served as Manager of Environmental Health and Safety in a high tech chemical manufacturing facility. There are some basic safety features that I used in my professional life. I’ll also say that I’ve been diving since 1959, am U.S. Navy trained in scuba, spent about 10 years as a pararescueman, and so am familiar with hazardous environments, diving included. I’m also a retired NAUI instructor (NAUI #2710).

In the occupational health and safety profession, we have what we call the “Hierarchy of Controls.” These controls show that the most effective to least effective controls are: Substitution/Elimination, Engineering Controls, Administrative Controls, and personal protective equipment (PPE) controls. Tech divers are almost entirely using administrative and PPE controls. The administrative controls are these procedures you are talking about for gas changes. The PPE is the different breathing mediums you are using, as well as the rest of the equipment you use.

But this equipment is also a problem for the technical diver. Having to carry back gas, bottom gas and gas for your decompression stops (50% oxygen, for instance, that can be toxic at depth) complicates the dive. It also presents ergonomic hazards of both mobility (limiting it), and choices for which gas to breath when.

Now, I saw a 15 point check list for each gas change in one of the comments, and others agreed that this is drilled into people by their training agency. When I was in the U.S. Air Force, and we had a complex procedure, we had checklists to look at. Pilots firing up a helicopter went through checklists, point by point. But I see no mention of written checklists being available for tech divers on their dives. It comes from memory.

On this dive, the instructor had to keep track of 8 students (almost an impossibly high number) while still going through ensuring that he’s using the correct procedures during the dive. This leads to ergonomic overload.

So with all these in mind, you won’t find me trying a tech diving course. I’ll stick to my river diving on air, even solo, which seems much safer than any technical deep dive. This retired safety and health professional thinks this style of diving is way too hazardous.

SeaRat

 

[LFMarm]

Written check lists are often used in technical diving for pre-dive checks. I started using them for CCR and I am now using for any complex dive.

 

[Nick_Radov]

But this equipment is also a problem for the technical diver. Having to carry back gas, bottom gas and gas for your decompression stops (50% oxygen, for instance, that can be toxic at depth) complicates the dive. It also presents ergonomic hazards of both mobility (limiting it), and choices for which gas to breath when.

Don't forget the travel gas!
Any mix can be toxic at a sufficient depth.
Once you're carrying multiple stages a DPV becomes pretty much mandatory if you have to cover any distance or deal with a current.

Now, I saw a 15 point check list for each gas change in one of the comments, and others agreed that this is drilled into people by their training agency. When I was in the U.S. Air Force, and we had a complex procedure, we had checklists to look at. Pilots firing up a helicopter went through checklists, point by point. But I see no mention of written checklists being available for tech divers on their dives. It comes from memory.

Pilots also have memory items for issues where there isn't time to read from a checklist. Regular technical diving is a lot simpler than flying a helicopter, at least in terms of number of procedures and how we react to mechanical failures.

On this dive, the instructor had to keep track of 8 students (almost an impossibly high number) while still going through ensuring that he’s using the correct procedures during the dive. This leads to ergonomic overload.

Yes. Proper technical training agencies limit the student-to-instructor ratio to 3:1 (or less depending on conditions). Unfortunately, in some developing countries life is cheap and people take shortcuts.

So with all these in mind, you won’t find me trying a tech diving course. I’ll stick to my river diving on air, even solo, which seems much safer than any technical deep dive. This retired safety and health professional thinks this style of diving is way too hazardous.

Accident analysis has shown that diving as part of an integrated team is far safer than solo diving (or "same ocean" buddy diving). River diving can be particularly hazardous due to low visibility, currents, boat traffic, and the risk of entrapment or entanglement by submerged obstacles. Although that doesn't necessarily apply to all river dive sites.

(I am just trying to set the record straight here, not convince anyone to take a tech diving course. It's certainly not for everyone.)

 

[John C. Ratliff]

Don't forget the travel gas!
Any mix can be toxic at a sufficient depth.
Once you're carrying multiple stages a DPV becomes pretty much mandatory if you have to cover any distance or deal with a current.

Pilots also have memory items for issues where there isn't time to read from a checklist. Regular technical diving is a lot simpler than flying a helicopter, at least in terms of number of procedures and how we react to mechanical failures.

Yes. Proper technical training agencies limit the student-to-instructor ratio to 3:1 (or less depending on conditions). Unfortunately, in some developing countries life is cheap and people take shortcuts.

Accident analysis has shown that diving as part of an integrated team is far safer than solo diving (or "same ocean" buddy diving). River diving can be particularly hazardous due to low visibility, currents, boat traffic, and the risk of entrapment or entanglement by submerged obstacles. Although that doesn't necessarily apply to all river dive sites.

(I am just trying to set the record straight here, not convince anyone to take a tech diving course. It's certainly not for everyone.)

Well, I’ve been diving solo for decades, and in rivers. Yes, there is entanglement, especially with fishing line, but nothing a sharp dive knife (yes, the BFK) that I carry on my leg cannot handle. Learning to use currents, and that currents on the surface are usually much higher than on the bottom. (There is a “bottom effect” in rivers, which allows a diver, or fish or to function fairly well on the bottom.). So far as the statistics go, there were two fatalities in this “Blue Hole” on the same day, from what I can decipher from the posts above, both tech divers. So I do question a bit about the accident analyses you state above. Both open circuit, with its multiple tanks, and rebreather diving with the inherent problems of anoxia from the breathing mixture and switches, seem to say to me (and I’ve been trained in accident analysis) that tech diving is much more hazardous than solo diving in a river, with a max depth of 23 feet.

SeaRat

PS, here are two of my dives, documenting lampreys spawning in the Clackamas River near Portland, Oregon.

 

[NothingClever]

I wouldn’t let the Russian Popeye video serve as an example of anything but the dim-witted side of SCUBA profiteering.

Like Nick said above - in some parts of the world, people are casually reckless, life is cheap and making a buck trumps better judgment.

If some jacka$$ got to close to the dam, got swept over and drowned, should we condemn all river diving?

 

[boulderjohn]

seem to say to me (and I’ve been trained in accident analysis) that tech diving is much more hazardous than solo diving in a river, with a max depth of 23 feet.

Yes, indeed. The fact that technical diving is more dangerous than NDL diving is emphasized in the tech program I taught, all for the purpose of making sure the divers took the training seriously.