80cu Tank at 800 Feet ????

[Akimbo]

What do you mean by the bolded statement, please?

Looking back... not my best word craft.

It was an attempt to illustrate that saturation diving is so common that the some diving bells don't even have time to be maintained for anything that is not mission critical or a safety risk. Paint will reduce corrosion and extend the working life of very expensive diving bell pressure vessels. Sacrificing that longer working life due to high demands is an indication of how many saturation divers are at work 24/7.

You may not see some bells on deck for 11 months unless they are swapping divers for shift change (10-15 minutes 2-3x/Day), WoW (Wait'in on Weather), moving locations, or for hurried repairs -- which usually puts the entire ship off contract. That gives a new meaning to working under pressure.

 

[Akimbo]

There is another aspect of physiology in rapid compression worth discussing: Compression arthralgia, or compression pains, can be painful to the point of limited mobility. Symptoms vary dramatically by individual and usually start around 600'. This is not the kind of thing you want to discover on an 800' bounce dive on Scuba, especially on top of all the other things that can go less than perfect.

It is not uncommon to take 24+ hours to press saturation divers down to the 1000' range. My brother was compressed too rapidly on a time-critical job in the late 1970s and actually couldn't complete his first lockout because of compression pains. It nearly got him run off (fired).

There are residual effects that can cause delayed arthritis. Does anyone really want to make bounce dives like this, for no financial reward, just to end up in a wheel chair 20 years later? That is if you aren't in a body bag first, assuming they can find the body.

There just isn't that much glory from a 2 minute clip on YouTube where nobody can see your face.

 

[speedyal]

If you read Diving Into Darkness, which is about the fatal dive which killed David Shaw, they spend about a week setting tanks for the dive to about 890 feet.

Many of the dives setting tanks were themselves decompression dives.

And those were all back-ups. Shaw was using a rebreather. As it happened however, it was a good thing they did stage the tanks. But I won't ruin it for you if you haven't read it...

Thats actually what interested me in this david shaw

 

[Rhone Man]

Thats actually what interested me in this david shaw

If you haven't read the book, I really recommended it. Fantastically written.

 

[Deep South Divers]

Have you seen this?



For what it's worth, I am only presenting this because it's publicly available and relevant to our thread. I am not passing judgement, criticizing, supporting or not supporting the dive, the desire to dive that deep, or otherwise trying to "scare" anyone.

In short, David Shaw was attempting to make the dive to retrieve the body of another diver. That diver had passed away some time earlier (months or years, I can't remember off the top of my head) and was finally located after many searches.

I recall that this event happened at Bushman's Hole in Africa, and that the divers were using heavily modified (read: oil-filled parts) Inspiration rebreathers.

 

[Akimbo]

Another thought on planning for deep dives came to mind last night. You must also account for, and carry, enough gas to equalize your drysuit. SAC rates are a "squishy" enough variable. What the heck is the equivalent for the drysuit equalization rate with extra heavy underware?

Lets see, 1000' would be 3000 PSI - 445 PSI – 135 PSI (usable gas pressure), blah blah, x… what's that volume again? What is trivial at 300' becomes critical 3x deeper.

Can you imagine the clip on YouTube where you had to abort your record setting attempt because your privates were being squeezed?
:homealone:

 

[speedyal]

Have you seen this?



For what it's worth, I am only presenting this because it's publicly available and relevant to our thread. I am not passing judgement, criticizing, supporting or not supporting the dive, the desire to dive that deep, or otherwise trying to "scare" anyone.

In short, David Shaw was attempting to make the dive to retrieve the body of another diver. That diver had passed away some time earlier (months or years, I can't remember off the top of my head) and was finally located after many searches.

I recall that this event happened at Bushman's Hole in Africa, and that the divers were using heavily modified (read: oil-filled parts) Inspiration rebreathers.

David Shaw died on 8 January 2005 whilst seeking to recover the body of Deon Dreyer, a South African diver who had himself died 10 years previously, and whose body Shaw had discovered at a depth of 270 metres (890 ft) of fresh water in Bushman's Hole, South Africa in October 2004.[2][4]

Shaw recorded his dive with an underwater camera and this recording relayed valuable information that allowed researchers to determine that he suffered from an effort-independent expiratory flow which resulted in an inability to match ventilation to the demands of physical work at that great depth.[5][6] Shaw ran into difficulties when he cut loose Dreyer's harness and the body unexpectedly began to float (Shaw had been advised by various experts that the body would remain negatively buoyant because the visible parts were reduced to the skeleton - however, within his wetsuit, Dreyer's corpse had turned into a soap-like substance called adipocere, which floats). Shaw had been working with both hands, and so had been resting his cable light on the cave floor.[7] Normally he would have wrapped the cable around his neck, but he had been unable to do so due to the helmet he wore with the camera. The lines from the body bag appear to have gotten tangled with the cable light, and the physical effort of trying to free himself led to Shaw's expiring. The next day, both of the bodies floated up to near the surface as the dive team was retrieving their equipment.

The dive which David Shaw died on was the 333rd of his career. At the time of his world record setting dive, he had been diving for just over 5 years.[8]



^^^^

This was from the wiki page on him he is an inspiring guy Im chomping at the bit to start into tech diving

 

[speedyal]

I forgot to post this but here is more info
Deep Cave Diving with Dave Shaw

 

[speedyal]

Another thought on planning for deep dives came to mind last night. You must also account for, and carry, enough gas to equalize your drysuit. SAC rates are a "squishy" enough variable. What the heck is the equivalent for the drysuit equalization rate with extra heavy underware?

Lets see, 1000' would be 3000 PSI - 445 PSI – 135 PSI (usable gas pressure), blah blah, x… what's that volume again? What is trivial at 300' becomes critical 3x deeper.

Can you imagine the clip on YouTube where you had to abort your record setting attempt because your privates were being squeezed?
:homealone:

Lmao maybe i can be the first person to scream ahhhhhh my nuts at 600 feet on you tube death from package constriction ?

 

[Akimbo]

Lmao maybe i can be the first person to scream ahhhhhh my nuts at 600 feet on you tube death from package constriction ?

Since there was never any reason for me to even ponder this complication, I suppose an engineering analysis is called for.

Question of the day:
Assume the crotch area of a drysuit is half a square foot or about 36 square inches. Let's say your argon bottle for equalizing the suit is empty at 600'. How much deeper can you go before your family name hits a road block?

BTW, what is Lmao?