Cozumel Incident 9/4/11

[Mossman]

If it was a dive to go anywhere past 100, they were inadequately equipped, and therefore the dive was inadequately planned and inadequately prepared.

Why make the cutoff 100'? Is 101' on an AL80 really much more dangerous than 99' on the same tank?

Plenty of recreational dive ops routinely escort divers down well below 100' on AL80s, some deeper than 130'. 100' is arbitrary and way too shallow to be any sort of cut-off point between safe recreational single-80 diving and technical multistage diving.

 

[MMM]

If it was a dive to go anywhere past 100, they were inadequately equipped, and therefore the dive was inadequately planned and inadequately prepared.

I'm going to disagree with this part of your statement. 130 feet is the generally established depth for recreational diving. I note that DAN's basic insurance level cuts out if you dive deeper than this.

 

[MMM]

Thanks David for your report. Do you, by chance, know if this was the first dive of the day for the divers involved? And if not, what their SI was? Not that it makes a huge difference given the profile...

 

[Ron Lee]

I'm going to disagree with this part of your statement. 130 feet is the generally established depth for recreational diving. I note that DAN's basic insurance level cuts out if you dive deeper than this.

Marg, you surely know this but DAN has two other insurance levels that do not have the 130' limit. I get the middle one just in case I see a mermaid at 135'.

 

[Tesibria]

...

1968 Neil Watson and John Gruener dived to 437 feet (133 m) on air in the Bahamas. Watson reported that he had no recollection at all of what transpired at the bottom of the descent due to narcosis.
1990 Bret Gilliam dived to a depth of 452 feet (138 m) on air. Unusually, Gilliam remained largely functional at depth and was able to complete basic maths problems and answer simple questions written on a slate by his crew beforehand.
1993 Bret Gilliam extended his own world record to 475 feet (145 m), again reporting no ill effects from narcosis or oxygen toxicity.
1994 Dan Manion set the current record for a deep dive on air at 509 feet (155 m). Manion reported he was almost completely incapacitated by narcosis and has no recollection of time at depth.

Emphasis added.

See also Deep Diving: An Advanced Guide to Physiology, Procedures, and Systems (by Brett Gilliam, Robert Von Maier) at page 127:

The dangers of this type of CNS O2 toxicity cannot be too greatly emphasized. On air, at 300 fsw (91 m) or 10 ATA, the PO2 has reached 2.1 ATA; this partial pressure will definitely produce toxicity limited only by time and other influences such as elevated PCO2.

For these indisputable facts, the practice of air diving deeper than 300 fsw (91 m) must be placed in the perspective of assumable risk of sudden death not just injury.
***
Neither Watson and Gruener (1968) nor Gilliam (1990) suffered O2 toxicity problems on their record dives to 437 and 453 fsw... respectively but their times in the critical toxicity zone were limited and they each had practice exceptional adaptive techniques. (In spite of this, Watson and Gruener reported near total incapacitation due to narcosis.)

So .. isn't your statement equivalent to saying that one CAN survive running a redlight while on a motorcycle and without a helmet, while a semi is barreling down on the intersection? I mean, it has been done before -- some people have survived such a stunt. ... ... ? And ?

 

[ScubaSteve]

http://www.scubaboard.com/forums/whine-cheeze/395611-wsopfans-rant.html

<snicker>



Sent from my iPhone using Tapatalk

 

[MMM]

Yes, I know this. That was why I referenced the basic plan. Like you, I have the middle plan but unlike you, it's in case I see mermen.

Marg, you surely know this but DAN has two other insurance levels that do not have the 130' limit. I get the middle one just in case I see a mermaid at 135'.

 

[Rescue Diver68]

Some people are more known quantities than others... Not trying to be insulting but if you were to have posted details about what was taking place in Cozumel or Bora Bora for that matter, why would anyone believe you with your 11 posts (currently) and living in Florida? Whereas many people who are discussing this (mostly behind the scenes in Private Messages and outside of SB) are key players in the Cozumel dive industry and have direct communications with people right in the middle of this.. They are not armchair quarterbacking.. But, everyone can deduce what they like..

You can almost be certain in most dive incidents / accidents there are people out there that know much more than the rest of people in these forums. Generally speaking, their priority is not to share information with you.. Be happy when it does happen and try to learn from it no matter if you believe all of what is disclosed or not..

Your account has basically contradicted that of one of the divers who was ACTUALLY on the dive himself. Your geographic location and number of posts on ScubaBoard hold no more credibility than anyone else. Is your stance that Heath is lying?
MMM posted that the dive took place on Santa Rosa and we know she posted a non-fact.

 

[MMM]

MMM posted that the dive took place on Santa Rosa and we know she posted a non-fact.

Oh for crying out loud. I explained myself, set the record straight and then deduced the actual site...which one of the family spokesperson "liked". I think you are beating a dead horse.

 

[Prop Joe]

Deleted. I had some links to deep diving records and books on the subject... I don't want to upset any one. No intent to disrespect. I've read many books on the subject and thought divers might be interested in reading about divers that have performed some of the deepest dives successfully.