More Deco Reading?

[HenrikBP]

it's boring as ****

Well, that sums it up

Henrik

 

[AndrewA]

Try "Deeper into Diving" by John Lippmann.

 

[rjack321]

I've read "Deco for Divers" and will re-read it. The Oxygen window and a few other topics are still a bit hazy

Can you recommend other books going into Deco, theory and practice. For actual diving I'd like to stay with the DIR system, but am up for any good info/reading on the topic.

I haven't read "Deco for Divers" but you'll find ALOT of information/descriptions out there which inaccurately describe the oxygen window. Many of them perpetuated by the "DIR" agencies. Stuff about milk trucks carting away N2 after they offload O2.

In actual practical practice the "O2 window" is a very large reduction in an inert creating an offgassing gradient without any lowering of absolute pressure by ascending. There's a miniscule increase in offgassing created by the metabolic consumption of O2 as described by Dr. Deco in the 2004 thread.

 

[PfcAJ]

There is some good stuff on the aquanaut list archives that George wrote. If you can get past the outrageous (and oftentimes hilarious) commentary, he wrote a lot about deco theory and practices. Its a lot to sift through, however.

 

[HenrikBP]

So to rephrase: by breathing - for instance - pure oxygen at say 20', all nitrogen is removed from breathing gas and therefore from the arterial blood, thus vastly increasing the gradient and influx of nitrogen into the blood without any change in depth - i.e. ambient pressure.

Right?

Henrik

 

[rjack321]

So to rephrase: by breathing - for instance - pure oxygen at say 20', all nitrogen is removed from breathing gas and therefore from the arterial blood, thus vastly increasing the gradient and influx of nitrogen into the blood without any change in depth - i.e. ambient pressure.

Right?

Henrik

Yes the "O2 window" can't get any bigger than breathing 100%.

But take a switch from 21/35 to EAN50 at 70ft after a 150ft dive. There's actually an increase in N2 so that's only minimally offgassing that because you've ascended from 150ft. But there's a massive 35% reduction in helium from the gas switch so rather than the piddly offgassing you've accomplished so far by ascending from 5.5ata to 3ata you suddenly have a massive helium gradient due to the replacement of He by O2.

 

[HenrikBP]

Yes the "O2 window" can't get any bigger than breathing 100%.

I understand - various depths and gas mixes will have different effects on what off-gasses and by what gradient. The 100% oxygen was just easier to wrap my head around

Thanks,

Henrik

 

[TSandM]

I didn't find the Mysterious Malady DVD dull . . . nor did Mike Boswell, who just borrowed it from me

I would also recommend the Lippmann and Mitchell book. It's another good one.

 

[TSandM]

I didn't find the Mysterious Malady DVD dull . . . nor did Mike Boswell, who just borrowed it from me

I would also recommend the Lippmann and Mitchell book. It's another good one.

 

[HenrikBP]

Being published in 1991, you still find Lippman's book "current" enough? I didn't find any newer editions.

Amazon.com: Deeper into Diving (9780959030631): John Lippmann: Books

Thanks,

Henrik