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ashling

(25,771 posts)
Fri Jan 18, 2013, 04:07 PM Jan 2013

Diving Deep into Danger



The first dive to a depth of a thousand feet was made in 1962 by Hannes Keller, an ebullient twenty-eight-year-old Swiss mathematician who wore half-rimmed glasses and drank a bottle of Coca-Cola each morning for breakfast. With that dive Keller broke a record he had set himself one year earlier, when he briefly descended to 728 feet. How he performed these dives without killing himself was a closely guarded secret. At the time, it was widely believed that no human being could safely dive to depths beyond three hundred feet. That was because, beginning at a depth of one hundred feet, a diver breathing fresh air starts to lose his mind.


***


Not everybody is cut out for the job. A diver cannot be claustrophobic or antisocial, because he must spend much of his time in a tiny sealed capsule with several other divers. He must be well-disciplined and perceptive, for he is likely to encounter a variety of unexpected hazards on the job. Many divers are military veterans, or have worked as roofers or mechanics. “The best are those who have a great deal of confidence in themselves and their abilities,” one former diver, Phil Newsum, told me. “You have to be willing to adapt to any situation. Philosophically, when you go out on a dive job, you’re expecting something is going to go wrong.”

Often, because of the depth, the job is performed in the dark, with only a headlamp to light the way. Divers have told me stories of sudden encounters with manta rays, bull sharks, and wolf eels, which can grow eight feet long and have baleful, recessed eyes, a shovel-shaped snout, and a wide, snaggletoothed mouth. One diver sent me a video, filmed from a camera in the diver’s helmet, of an enormous turtle that was playing a game of trying to bite off the diver’s feet and hands every few minutes. The diver finally sent the animal swimming away by pressing a power drill to its head. Someone else sent me a photograph of a diver riding a speckled whale shark, as if on a rodeo bronco.


http://www.nybooks.com/articles/archives/2013/feb/07/diving-deep-danger/
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Diving Deep into Danger (Original Post) ashling Jan 2013 OP
I usually start losing my mind upon entry. Scuba Jan 2013 #1
I lost my mind too ashling Jan 2013 #2
Yeah you do. You dive into the viewfinder. Scuba Jan 2013 #3
Love to read about it mokawanis Jan 2013 #4
Nitrogen narcosis (experience it!) Tuesday Afternoon Jan 2013 #5
 

Scuba

(53,475 posts)
1. I usually start losing my mind upon entry.
Fri Jan 18, 2013, 04:18 PM
Jan 2013

It's almost surreal down there and you can certainly get lost in the beauty.

Thanks for the post.

Tuesday Afternoon

(56,912 posts)
5. Nitrogen narcosis (experience it!)
Fri Jan 18, 2013, 06:51 PM
Jan 2013

Narcosis while diving (also known as nitrogen narcosis, inert gas narcosis, raptures of the deep, Martini effect), is a reversible alteration in consciousness that occurs while diving at depth. The Greek word ναρκωσις (narcosis) is derived from narke, "temporary decline or loss of senses and movement, numbness", a term used by Homer and Hippocrates.[1] Narcosis produces a state similar to alcohol intoxication or nitrous oxide inhalation, and can occur during shallow dives, but usually does not become noticeable until greater depths, beyond 30 meters (100 ft).

Apart from helium, hydrogen and probably neon[citation needed], all gases that can be breathed have a narcotic effect. This effect is consistently greater for gases with a higher lipid solubility and there is good evidence that the two properties are mechanistically related.[2] As depth increases, the mental impairment may become hazardous. Although divers can learn to cope with some of these effects, it is not possible to develop a tolerance. While narcosis affects all divers, predicting the depth at which narcosis will affect a diver is difficult, as susceptibility varies widely from dive to dive, and between individuals.

When narcosis appears, it may be completely reversed in a few minutes by ascending to a shallower depth with no long-term effects. For this reason, narcosis while diving in open water rarely develops into a serious problem as long as the divers are aware of its symptoms, and may ascend to manage it. Diving beyond 40 m (130 ft) is generally considered outside the scope of recreational diving: as narcosis and oxygen toxicity become critical factors, specialist training is required in the use of various gas mixtures such as trimix or heliox.

more at link:
http://en.wikipedia.org/wiki/Nitrogen_narcosis

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