No Technical Training for Me.

[Mr.X]

No one. I don't follow all of GUEs recommended gases either. Who said anything about GUE here? GUEs choice is 50% for a single deco gas in the ocean. All you people who think I'm a koolaid drinking gooey lemming need to read my profile.

This is getting stale.

x

 

[Soggy]

Here´s an example-profile where 80% is "better":
55m, 30m BT, BG 21/35, v-planner (nominal):
Deco (ean 40 & 80): RT: 65mins, OTUs: 88, CNS%: 34,4
Deco (ean 50 & 100): RT:65mins, OTUs: 93, CNS%: 40,4

Now Soggy may feel that standard gasses are more important than getting out of the water "cleaner" (less OTUs & CNS%) but if he wanted to, for the same effort and cheaper, he could...

I guess I don't understand your point here. The oxygen clock has been proven to be a bunch of BS for a long time. Are you worried about 6% CNS? Do you feel that makes for a better choice given the other issues (less N2 offgasing, less O2 available for surface breathing in the event of a hit, etc)?

Besides, a "better" choice in that dive would be to use 18/45 on the bottom rather than pushing your O2 and narcotic depth on the bottom when you are working.

 

[Thalassamania]

No one. I don't follow all of GUEs recommended gases either. Who said anything about GUE here? GUEs choice is 50% for a single deco gas in the ocean. All you people who think I'm a koolaid drinking gooey lemming need to read my profile.

Sorry, I guess I let Unc slip me a little of his kool-aid when I wasn't looking.

 

[Rick Murchison]

Actually, I *want* people to think about it because it's obvious that many people do not. You can dive whatever you want. I still think 80% is a silly choice.

No you don't. If you did, you wouldn't say it's a "silly choice." You would rather present a sound scientific reason why using oxygen is better. Yet you then cite an example where 80% saves a minute of deco time, and then turn your nose up at it because it's only a minute and therefore "silly."
Why do you consider that "silly?"
Stick to your specific example, and tell us why 80% is "silly."
Rick

 

[do it easy]

Soggy - just to play the devil gas' advocate, what problems would there be with using 80% O2 and 20% helium? Or 20% argon, if using a trimix bottom gas? There would still be no inerts that you trying to offgas, and breathing helium or argon at 30' isn't going to be much of an issue.

 

[Soggy]

No you don't.

Don't put words in my mouth. You don't have any idea what my desires are. I want people to think. There isn't enough of that around here.

If you did, you wouldn't say it's a "silly choice." You would rather present a sound scientific reason why using oxygen is better.

I did give several reasons why 80% is a poor choice, whether you agree with them or not.

Yet you then cite an example where 80% saves a minute of deco time, and then turn your nose up at it because it's only a minute and therefore "silly."
Why do you consider that "silly?"

One minute of advantage over a 90 minute period of time? Compare that to the added labor of mixing, the surface usefulness of O2, the fact that N2 does nothing positive for you....seems obvious to me.

Aww, forget it. I'm done. I'm apparently not particular good at explaining myself. This is one of those things that seems so incredibly obvious to me, that I can't even describe it.

You all have fun on your 80%. I'll be 20' above you diving with someone else.

 

[grazie42]

Originally Posted by Soggy
I guess I don't understand your point here. The oxygen clock has been proven to be a bunch of BS for a long time. Are you worried about 6% CNS? Do you feel that makes for a better choice given the other issues (less N2 offgasing, less O2 available for surface breathing in the event of a hit, etc)?

Besides, a "better" choice in that dive would be to use 18/45 on the bottom rather than pushing your O2 and narcotic depth on the bottom when you are working.

So 1,36Po2 on the bottom is "pushing it", and so is 32m end (~107ft)?
At the same time, thinking about 6% of CNS, is unimportant?
I don´t count on having my decogas in the event of a hit, thats why I carry separate O2, feel free to include "leftover decogas" in your accident management plan...

One might suggest that you should revisit your reasons for seeing 100% as "incredibly obvious" since it seems you´re not very good at explaining why that is so (though I am obviously not doing better with 80%)...

Since you´re done with this thread....Safe dives!

 

[Soggy]

So 1,36Po2 on the bottom is "pushing it", and so is 32m end (~107ft)?
At the same time, thinking about 6% of CNS, is unimportant?

Yes...

 

[MXGratefulDiver]

How is a downcurrent on 80% at 30ft is safer than on O2 at 20ft?! This sounds suspiciously like the buoyancy argument, which is a bunch of BS.

It's not ... but what happens when a current suddenly decides to take you from 20 feet to 30 feet? ... or deeper? Been on walls (Quadra Island, Neah Bay) where downcurrents can take you fairly quickly.

Ever dive in big waves? How about when those waves are pounding into a big rock a couple hundred feet or so from where you're trying to hold your stop? Even better ... try it while holding onto a spool and bag.

What I'm saying is that I'd consider not pushing my PO2 levels and give myself a bit of margin under those conditions ... even if it means I'll have to stay there a few minutes longer. It ain't a question of buoyancy control ... you're diving in a washing machine. Anybody who thinks his buoyancy control skills can instantly compensate for the force of a surge or downcurrent is kidding himself ...

... Bob (Grateful Diver)

 

[Soggy]

It's not ... but what happens when a current suddenly decides to take you from 20 feet to 30 feet? ... or deeper? Been on walls (Quadra Island, Neah Bay) where downcurrents can take you fairly quickly.

Ok, what happens when you go from 30 ft to 40 ft quickly? My point is that 80% doesn't change the situation. Or are you suggesting using 80% at 20' to compensate? If you are, why not use 100% at 15' where you still have the same offgasing rate (because there is no N2)?

Ever dive in big waves? How about when those waves are pounding into a big rock a hundred feet or so from where you're trying to hold your stop? Even better ... try it while holding onto a spool and bag.

All the time. How does 80% fix this?