Doc Deep dies during dive.

[Akimbo]

... Since it has never been done before, I wonder how the software is able to provide the numbers.

That is the mistake some people make. It is not dive profile software, it is a series of software algorithms that attempts to simulate decompression requirements for the average diver. The software blindly crunches numbers.

Somebody ran the numbers for a dive to the Titanic (3,800 m/12,500') and the software let them -- no mention of the fact that a full cylinder would probably be crushed by the differential pressure before reaching the bottom.

The software currently has limits programmed for things like PPO2 and the O2 clock but not:

• Compression Neuralgia
• Gas mixing tolerances (+/- 1% O2 is fine for Nitrox at 130')
• Gas purity tolerances
• Gas requirements for BC inflation
• Gas requirements for drysuit inflation
• HPNS
• Lung ventilation rates (RMVs) for varying gas densities and work loads
• Minimum breathing gas temperature versus time to prevent the onset of pneumonia
• Respiratory heat loss based on ambient water temperature, the mix, and RMV
• Thermal protection requirements
• Usable gas at depth (cylinder pressure minus (ambient pressure + first stage IP) x cylinder volumes)
• WOB (Work of Breathing). There are reasons that commercial divers don't use Trimix

I'm sure I forgot a few constrains but overlooking part of this list is enough to kill you before they would matter anyway.

 

[Carl_F]

That is the mistake some people make. It is not dive profile software, it is a series of software algorithms that attempts to simulate decompression requirements for the average diver. The software blindly crunches numbers.

Somebody ran the numbers for a dive to the Titanic (3,800 m/12,500') and the software let them — no mention of the fact that a full cylinder would probably be crushed by the differential pressure before reaching the bottom.

From what I can tell, a full cylinder is likely going to be ok at those depths (5600 psi external pressure vs 3000 psi internal pressure) but ...

I have been surprised that available decompression software allows one to extrapolate beyond the data that the algorithm has been benchmarked against. (It makes for a fun discussion to see a decompression profile for a dive to the Titanic and the amount of gas needed with the basic assumptions but it's entirely worthless.) In my industry the codes used to predict outcomes is heavily benchmarked and it's clear when the user is extrapolating beyond the benchmarked data (and the relevant oversight agencies frown on that ... or at least ask for the additional benchmark data that demonstrates acceptability of the model to the limits you want to use it.)

 

[Akimbo]

From what I can tell, a full cylinder is likely going to be ok at those depths (5600 psi external pressure vs 3000 psi internal pressure) but ...

I analyzed a full steel HP 80 with solids modeling and FEA (Finite Element Analysis) software a few years ago and it started to deform around 9,800'. A friend was exploring options for generating acoustic signals on the cheap between 8,000 and 15,000'.

An Aluminum 80 would probably do better because of the thicker wall. Unlike a submarine, there are no ribs in a Scuba tank designed for internal pressure.

 

[Hetland]

I have to wonder just how the decompression and gas management was derived for this “dive plan”. Could it be as simple-minded as just typing in the depth and RMV into a piece of software?

I attempted this when the news came out that he had passed. I want to say I used both Z16 and VPM, but don't make me swear to it.

The end result was that his "plan" was suicideally short on both decompression time and gas supplies (not taking into account that other divers could have provided him with additional bottles).

 

[Akimbo]

I attempted this when the news came out that he had passed. I want to say I used both Z16 and VPM, but don't make me swear to it.

The end result was that his "plan" was suicideally short on both decompression time and gas supplies (not taking into account that other divers could have provided him with additional bottles).

I'm shocked. Shocked!

[video=youtube;SjbPi00k_ME]

 

[kwinter]

I am constantly trying to keep my ego in check because there are so many people telling me how amazing of a diver I am. Even my wife keeps hassling me to buy more dive gear because of how incredible I dive. She wants me to buy a scooter next..


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Arin - Garth's been stealing drugs from work again.


iPhone. iTypo. iApologize.

 

[Kevrumbo]

An intrepid yet naive, courageous but ultimately tragic endeavor:

For every successful Felix Baumgartner and his 23 mile free fall record from the edge of Space --there is a Nick Piantanida (and a similar fate as "Doc Deep" Guy Garman) that leaves a wake in passing. . .

. . .Ultimately, each person who ventures out must make his or her own decisions about how far to go and what point to turn back. There's an old saying among prospectors who comb the hills for gold here in the American West: "Gold is where you find it". You can say the same about adventure ["Adventure is where you find it"]. For that matter, you can say it about risk, about death, and about being acutely alive. . . --from Introduction, Last Breath: Cautionary Tales From The Limits of Human Endurance by Peter Stark.

 

[CT-Rich]

I am constantly trying to keep my ego in check because there are so many people telling me how amazing of a diver I am. Even my wife keeps hassling me to buy more dive gear because of how incredible I dive. She wants me to buy a scooter next..


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Garth, how much life insurance do you carry? And let me guess, is it in her name?

 

[Garth]

Garth, how much life insurance do you carry? And let me guess, is it in her name?

Lol, I forgot I wrote this post. It was a joke. My wife does not want me to buy a scooter otherwise I would have one immediately. I wouldn't even be able to listen to someone who was trying to flatter me about my diving, I'm too critical of my self anyways and for good reason. I'm proficient enough to be safe which is a start.

Life insurance is a pretty good policy but not a ton of money. I'd want it to go to her anyway.

 

[boulderjohn]

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A ScubaBoard Staff Message...

A little off topic joking in a thread is OK and often even welcome. Let's not take it too far, please. The topic of this thread is a serious one.

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