200' on air for 5 min bottom time?

[DivemasterDennis]

I hope the op gets the clear message and consensus of the responses, which come from a really good collection of divers in the know. And that message is- you are not qualified to do the kind of dive you present, and to try to learn how to do by on line conversation is not wise. I like a good discussion on deco profiles, gas choice and deep diving as much as the next guy, but at 20 dives I benefitted more from conversation about buoyancy, air consumption, and the like.
DivemasterDennis

 

[Dive Bug Bit Me]

I still don't see how you get an 18 min dive. Do you have a chamber frequent flyer card?

Thats another problem with these. If you don't log dives that last less than 20 minutes, then this doesn't even count for the log book. Can't use them as experience for courses! :d

If you really do the math, then at the bottom only fast tissue compartments become a limiting factor in 5 mins bottom time. Advantage is they clear quickly on the way up (unless you overstay your bottom time.)

 

[Colliam7]

Doing the math quickly in my head, Colliam7's V-planner would also give an 18 minute dive.

Actually, it would be just a bit longer - 23 min: 1) 4 min descent @ 50 fpm, 2) 5 min at 200 feet, 3) 11 min for ascent (@ 30 fpm) to 20 feet) 4) 1 min @ 20 feet) 5) 2 min @ 10 feet.

 

[drbill]

This is the type of situation that Darwin likes to step in and answer... only you won't be there to receive the Award.

I did a lot of deep air diving (always stopping at 200 ft) but I did it with 40+ years of diving experience and a gradual increase in depth over a few months to test my response to narcosis.

 

[oldschoolto]

What plan? Do you have a chamber frequent flyer card?

Now that's frick'n FUNNY......

Jim....

 

[BenjaminF]

Do you have a chamber frequent flyer card?

Do they offer every 6th trip free, with drinks on every 3rd trip?

 

[Bob DBF]

What plan?

I still don't see how you get an 18 min dive. Do you have a chamber frequent flyer card?

Navy tables ( USN Dive Manual rev6) calculates to 15.1min

• 75fpm decent 2.7 min
  5 min bottom time
  30fpm ascent
  deco stop @ 20' for 1 min
  total ascent time 7.4 min (includes deco)

I also believe it is rather sketchy for a dive plan, but in my youth.....

Intellectual knowledge of Narcosis does not mitigate it's effect. If you are lucky the problem you have while narked will school you rather than kill you but, at 200' on an 80 there isn't much time to learn.



Bob
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A man's got to know his limitations.
Harry Callahan

 

[Jared0425]

Narcosis does not kill folks, it's the actions you do that causes your own demise. Narcosis can be handled with experience and the know how to get a handle on it.

 

[TSandM]

The question of whether narcosis can be "handled" is a very contentious one. There are pages and pages of threads on deep air. We will never agree about it. Having made three errors when narced that could have killed my team, I know where I stand.

 

[Peter Guy]

Narcosis can be handled with experience and the know how to get a handle on it.

Very interesting comment and probably true -- except when it isn't. My guess is that this is on of those -- "As long as nothing is out of the ordinary" type situations. The book "Terrible Hours" about Navy hard hat divers has some discussion of this -- the narcosis just made decisions much harder.