Question True requirements to deserve the title of Master Diver???

[boulderjohn]

@boulderjohn Do you have a link to the incident report/article? I'm trying to figure how anyone with even the most cursory knowledge of diving would go "Yeah, an AL-80 is plenty of air for a 300 foot dive." Like, even assuming they didn't know about MOD, and somehow didn't notice the Navy tables stop at 130 ft for a reason, they would've needed a ridiculously low SAC to have anywhere near enough air on one tank. Like, how on earth does this happen?

Thread 'Scuabamau diving accident'

Sep 4, 2011

Hi All- This note is hard to write. Opal, Gabi Loco and another guest diver where hurt on a dive that should not have taken place.
First of all Opal is in the hospital as you read, unconscious and paralyzed and on a respirator. Gabi now has feelings in his legs after the chamber ride. The guest diver so far is recovering well after his ride. I am sure there will be more scheduled.
There are four divers going in the chamber with Opal to help her breath while she does her first ride. It is not good.

Ok you want to know what happened. They went to three hundred feet on air. No one knows...

• firstdive2005
• Replies: 584
• Forum: Cozumel

Be careful reading it. The thread starts with intentional misinformation. When they got back to the boat, they pretended they had been caught in a down current that took them to those depths. You have to go quite a ways in before you get the truth, and eventually you see the post by the DM admitting the truth.

The truth is that the three of them wanted to do a bounce dive to 300 feet, with the shop owner (Opal Cohen) and her DM (Gabi Loco) on AL 80s. Her boyfriend was on an AL 100. At 300 feet, Opal continued to descend. (When I went to Cozumel after it, people were divided as to whether she kept going because she was narced or passed out because she was narced.) Gabi went after her and turned her around at 400 feet while the boyfriend stayed at 300. On the ascent, Opal and Gabi ran out of air, and they did a 3-way buddy breathing ascent.

According to their plan, the dive should not have taken more than maybe 14 minutes, and they figured they had enough for that amount of time.

During the discussion, I was in contact with another professional from Cozumel who couldn't figure out how they ran out of air. Why, I was asked, did that short dip from 300-400 feet have such an impact? I had to explain Boyle's Law to that professional.

 

[CRT2]

Could it have been CNS Oxygen toxicity? Rather than narcosis?

 

[boulderjohn]

Could it have been CNS Oxygen toxicity? Rather than narcosis?

I don't believe we truly understand all that can happen with oxygen toxicity, so I suppose it is possible, but it was not a seizure. She was able to ascend on her own after the DM reached her, and a 3-way buddy breathe requires some skill. The assumption most people had was that she was so narced she just kept swimming down. I heard the "passed out" version from a DM in Cozumel. Bret Gilliam once told me that (believe it or not) on their deep diving exploits, Sheck Exley would sometimes pass out at depth and then wake up again and continue the dive.

 

[boulderjohn]

@boulderjohn Do you have a link to the incident report/article? I'm trying to figure how anyone with even the most cursory knowledge of diving would go "Yeah, an AL-80 is plenty of air for a 300 foot dive." Like, even assuming they didn't know about MOD, and somehow didn't notice the Navy tables stop at 130 ft for a reason, they would've needed a ridiculously low SAC to have anywhere near enough air on one tank. Like, how on earth does this happen?

If everything had gone well, the air supply is not as ridiculous as you might think.

Let's assume a SAC rate of 0.5 cubic feet. (I am sure they all could do that--Opal and Gabi could easily do better.) The average depth to 300 feet is 150 feet, for an average ATA of 5.6.

Descent
Skilled divers can easily descend at 100FPM, so the descent would be 3 minutes.
3 * 0.5 * 5.6 = 8.4
Let's round off to 10 cubic feet for the descent.

Ascent
Let's assume a 30 FPM ascent. If they went straight to the surface at that rate, it would take 10 minutes.
10 * 0.5 * 5.6 = 28.
Let's round off to 30 cubic feet for the ascent.

With AL 80s, that leaves nearly half the tank for decompression/safety stops. I would bet they and other Cozumel regulars have done it before.

That's if everything had gone well. Technical training teaches you to assume everything will not go well and prepares you for the things that could go wrong.

 

[Wibble]

This really does show the difference between the philosophy of technical and "recreational" divers. A technical diver would not even think of a stupid dive like a single ali 80 for a 90m/300ft bounce dive. TBH it's about as crazy as the "free divers".

A technical diver would use the right gases (with helium), with redundancy including catering for failures and a sensible bottom time too -- on a rebreather.

Isn't the Blue Hole littered with the corpses of recreational divers venturing into the technical diver's realm?

 

[Cthippo]

This really does show the difference between the philosophy of technical and "recreational" divers. A technical diver would not even think of a stupid dive like a single ali 80 for a 90m/300ft bounce dive. TBH it's about as crazy as the "free divers".

A technical diver would use the right gases (with helium), with redundancy including catering for failures and a sensible bottom time too -- on a rebreather.

Isn't the Blue Hole littered with the corpses of recreational divers venturing into the technical diver's realm?

And this, right here, is why the Master Scuba Diver certification is meaningless, at least in this community.

MSD is a fundamentally recreational cert and, as Wibble posted and many people will agree, no recreational diver is considered accomplished on this forum. I don't think this is a healthy approach, but I am not here to change a culture.

 

[BoltSnap]

Bret Gilliam once told me that (believe it or not) on their deep diving exploits, Sheck Exley would sometimes pass out at depth and then wake up again and continue the dive.

I don't believe some of the shiit he used to tell.

 

[scubadada]

Have earned a masters degree or higher degree and also dive.

So, I guess I am a Doctor Diver

 

[SouthernSharktoothDiver]

@boulderjohn Yeah, I did similar math and came to about the same conclusion after I made my earlier comment. My question at that point would be...why? Yo-yoing three hundred feet into the ocean, a hundred feet past my MOD, with a razor thin air margin and no backup equipment does not seem even remotely worth doing. What could you possibly see/do down there in the thirty seconds or whatever you're actually at your stop depth that's worth the risk? And if you're ok with being reckless about this stuff, why not just get some trimix fills and do a little DIY tech diving? Sure, it'd still be way more dangerous than actually diving with training, but at least you've got the right gas mixes, equipment, and a plan.

 

[boulderjohn]

What could you possibly see/do down there in the thirty seconds or whatever you're actually at your stop depth that's worth the risk?

In Cozumel, at 300 feet there is old, non-living reef, and everything is kind of a blue/gray color. There aren't many fish. As you ascend, you will find some black coral and lion fish at around 200 feet.