Deep Air Diving - thoughts

[Belmont]

Just an idea here: would it be risky to bring on a trimix dive, say to 180 feet, a stage with air for the purpose of experiencing narcosis and then switch to backgas to complete the dive, all this under the supervision of an instructor.

This way the OP would be able to experience narcosis on a deep dive but in a controlled situation and thus satisfying his desire to experiment in a safer way.

 

[Thalassamania]

You want to try air at depth with complete safety? That's one of the things chambers are for.

 

[Belmont]

You want to try air at depth with complete safety? That's one of the things chambers are for.

Please explain.

The OP wants to try diving to 150-200 feet to experience narcosis on air.
I mentioned that if he wanted it so bad he could try going down on trimix and then breathe some air from a stage brought for the purpose, experience the effects and do some supervised tests and switch back to trimix when finished then come up safely doing all the deco stops needed.

How would that require chamber time more than the same dive done on air?

Also, I did say "safer way" not "complete safety".

I'm not trimix trained and do not intend to dive beyond recreational depths myself.
I brought this point to see if it had been tried in the past or if it could be used in the scope of a tech course.

 

[Hank49]

It wouldn't require chamber time. He's just stating that to be completely safe from drowning, you can do any depth in a chamber.....which brings the question I was thinking after reading Thal's post. Can you like....just walk into the San Pedro chamber and say, "dude, can you take me down to 200 feet"? ??? I think you'd need some special connection...or a lot of money.

 

[Thalassamania]

Many chambers have some sort of "chamber dive" program. Dives are usually to 160, often can accommodate 4 or so and last time a checked (a few years back) a couple of hundred bucks. Call them.

 

[shoredivr]

The Reimer chamber in Hamilton, Ontario, Canada, has two chambers; one goes to 150 ft, the inner chamber goes to 200 ft.

It cost a group of us $100 each IIRC to go down to 200 feet and it was very educational for me.

 

[Kevrumbo]

$20 each here at the Catalina Hyperbaric Chamber for an Orientation Dive to 165'. . .

 

[Bismark]

Now to find 8 people who can all agree on the deco profile...................

Might be interesting to offer a problem solving experiment where the parameters are established to create a "non-recoverable" situation if the problem is not solved correctly within specified time limits. I would be very interested to see the results. This must have been done somewhere?? I remember from my air force days when we got to experience hypoxia in a chamber and that lesson was driven home very strongly..........

 

[Kevrumbo]

Here's one set of simple deco profiles used for my Chuuk/Subic Bay Trip last year Nov-Dec:

150'/45m for 20min;
160'/48m for 15min
170'/51m for 10min
180'/54m for 5min.
(Choose one and only one of the above for a square bottom profile, and stick with it at the particular depth of interest)

The Deco Profile and time on Nitrox 50% is the same (20min) whichever depth and corresponding bottom time you choose above. Full parameters listed here.

(Note: the above works for 21/35 Trimix as well as an Air Mix)

Keep tasks very simple on Deep Air dives: only minor brief penetrations into crew & engine spaces; primarily tours & surveys of open cargo bays and outside ship's superstructure.

 

[peterbj7]

I'd take someone to 200' in water for much less than a chamber ride, though I'd want to do at least two or three dives with them first.