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.