200' on air for 5 min bottom time?

[chrpai]

Hypoxic. Good luck getting some without some He in it. Also good luck with even more deco and narc. Also good luck finding a dive computer that will handle it.

 

[boulderjohn]

Hypoxic. Good luck getting some without some He in it. Also good luck with even more deco and narc. Also good luck finding a dive computer that will handle it.

Although I agree that it will be tough to get that mix, a Shearwater computer will handle it. I just tried it.

As for hypoxic, my computer gives me a hypoxic warning here every time I dive on air. At this altitude, the surface PPO2 of air is .176. So I am breathing an hypoxic mix every hour of every day I live in Colorado. If I go up into the mountains, I am really hypoxic.

 

[Dr. Lecter]

As for hypoxic, my computer gives me a hypoxic warning here every time I dive on air. At this altitude, the surface PPO2 of air is .176. So I am breathing an hypoxic mix every hour of every day I live in Colorado. If I go up into the mountains, I am really hypoxic.

Nice. This makes me want to take my Petrel with me next time I hit a 14er or go to Breck.

 

[tracydr]

A lot of divers, maybe the majority, have no idea how to find such an answer. I lot of divers, maybe the majority, have no idea how to access the Navy Dive manual. A lot of divers, maybe the majority, know so little about deep diving and decompression theory that they think the answer to such a question is ironclad and simple.

A lot of people have a reflexive need to go to social media for answer they could have gotten better somewhere else. If you were to go to the Instructor to Instructor forum, you will frequently see people ask questions like what is the PADI standard for ABC, or what is your understanding of PADI standard DEF. They then get a variety of answers. In the same amount of time that it took the OP to write the question, and the same amount of time it took for others to write their best guess responses, any one of them could have opened their instructor manuals or written an email to PADI for a definitive answer.

Its hard to realize that the younger generation has never done research without a computer. They might write a research paper without ever doing any research involving a library or actual "research". They rely on Wikipedia.
My husband teaches a graduate school class on Research Methods. Every class he has at least 1-2 students caught plagiarizing. He catches them using a computer program designed to pick it up.
these are graduate students and they usual don't even realize they plageurized, unless they copy from somebody else's paper.

 

[boulderjohn]

My husband teaches a graduate school class on Research Methods. Every class he has at least 1-2 students caught plagiarizing. He catches them using a computer program designed to pick it up.
these are graduate students and they usual don't even realize they plageurized, unless they copy from somebody else's paper.

Has anything really changed?

The fact that your husband has the computer program that catches plagiarism puts him ahead the way things were 40 years ago--he just wouldn't have caught them then.

I can't remember the exact numbers, but I read a story about a Berkeley professor who tried one of those programs for the first time. (This was quite a while ago, when Internet research was still pretty new.) He announced to his very large lecture class that he was gong to try the program. When he did, he caught something like 40 cases of plagiarism. In his previous 20 years of teaching, he had only caught two cases. That does not mean he wasn't actually having more than 40 per year that he didn't catch.

When I was in college (more than 40 years ago), I knew people who hired typists to type papers they had gotten from someone else. Not only had they not written the papers they handed in, they hadn't read them.

When I was teaching at the University of Colorado in the 1970s, I nailed a student for plagiarism. He was incensed. Everyone does this, he argued. He threatened to take me to the Dean. I told him go ahead. The Dean, of course, supported me. The point of that story is that the student was shocked that the Dean supported me. He really did think everyone did it. He really did think there was nothing wrong with it.

Plagiarism in writing papers is chiefly a result of the instructional procedure used. When I was a freshman in college, my English teacher used a method that pretty much made it impossible. I used it ever since, and when I was a curriculum director, I required it of my curriculum writers.

 

[chrpai]

Although I agree that it will be tough to get that mix, a Shearwater computer will handle it. I just tried it.

That's not your typical computer. If someone owned one of those, I doubt they would be asking such a stupid question in the first place.

 

[tracydr]

The effects of NO2 Narcosis can be mitigated to a degree. This is specific to an individual and tolerance of narcosis will change from one day to another. Adaptation has been shown to occur in numerous experimental dives. The research I was involved in took place at DCIEM in the 70's. Tests were administered to various subjects (non-trained divers/science students from the University of Toronto and Navy Divers) and included a series of Reasoning and Mathematic problems. These were taken on the surface and at various depths in the Chamber. The mechanics of narcosis adaptation are not yet understood. Progressively deeper dives over time will in-fact mitigate the symptoms. They can't however be removed.

Everyone regardless of training or experience will experience the effects to varying degrees. It effects different people, in different ways, at different times. A Diver who regularly faces deep exposures, will often exhibit a tolerance that far exceeds a Diver who has not adapted over time. Training in Deep-Air will help the diver identify and monitor his mental condition and assess when the dive should be terminated. It's all about establishing the Diver's safe diving envelope in a meaningful way to him.



I agree. You wouldn't go into a Cave without proper training, why would you venture deep an air?

Do divers lose that adaption ability, if they don't deep dive for a certain amount of time or do they remain adapted. For instance, would an adapted diver have similar narcosis 6 months to a year after having become adapted, if they don't dive deep during this time?

I ha a boyfriend who was a commercial diver and Vietnam vet, diving in Vietnam as an SF soldier. He dived commercially in New Orleans after the war.
He became mentally addicted to the feeling of narcosis and sought out nitrous oxide gas after he retired from commercial diving. He ended up falling asleep under the covers while using gas. He died from an overdose of nitrous oxide.
I know that he didn't commit suicide and also know that he had been using the gas recreationally for quite awhile. It was a terrible accident. However, he did first experience narcosis while doing 200-250 foot deep air dives and told me repeatedly how much he liked the feeling of narcosis. He passed away 13 years after his third tour of Vietnam.
I'm sure he may have died from an overdose of some other drug, had he not died of laughing gas. Unfortunately, he thought this was a better substitute than street drugs.

 

[redacted]

Do divers lose that adaption ability, if they don't deep dive for a certain amount of time or do they remain adapted. For instance, would an adapted diver have similar narcosis 6 months to a year after having become adapted, if they don't dive deep during this time?

I ha a boyfriend who was a commercial diver and Vietnam vet, diving in Vietnam as an SF soldier. He dived commercially in New Orleans after the war.
He became mentally addicted to the feeling of narcosis and sought out nitrous oxide gas after he retired from commercial diving. He ended up falling asleep under the covers while using gas. He died from an overdose of nitrous oxide.
I know that he didn't commit suicide and also know that he had been using the gas recreationally for quite awhile. It was a terrible accident. However, he did first experience narcosis while doing 200-250 foot deep air dives and told me repeatedly how much he liked the feeling of narcosis. He passed away 13 years after his third tour of Vietnam.
I'm sure he may have died from an overdose of some other drug, had he not died of laughing gas. Unfortunately, he thought this was a better substitute than street drugs.

How does an overdose of nitrous oxide directly cause death? Was there not sufficient O2 in the gas to support life?

 

[Dr. Lecter]

Do divers lose that adaption ability, if they don't deep dive for a certain amount of time or do they remain adapted. For instance, would an adapted diver have similar narcosis 6 months to a year after having become adapted, if they don't dive deep during this time.

And how would a newly minted cave diver's abilities look 6 months to a year after having become trained, if they don't dive overheads during this time?

 

[chrpai]

Auto erotic asphyxiation... what a way to go. Lost a schoolmate that way many years ago. You inhale a whippet and hold it to let the effect take over. Just as you start to blackout you breath... or so you hope.

RIP Joe.