Gas density guidelines

[Dr Simon Mitchell]

Hello

The Rebreathers in Scientific Diving Oroceedings (papers from a joint AAUS / NOAA / DAN / US National Parks Service conference held at Catalina Is in Feb 2015) have just been released today.

https://www.omao.noaa.gov/sites/def...rs and Scientific Diving Proceedings 2016.pdf

In it (page 66) is a paper on respiratory physiology and diving which contains the first evidence-based guidelines on gas planning to ensure gas density falls within a safe zone. The paper describes the data which justify the limits, and provides a guide to calculating gas density.

The proceedings contain a variety of other papers including one on decompression which discusses the deep stops controversy being debated on a thread in the technical diving forum. Please don't discuss deep stops here.

I am happy to answer any questions related to the respiratory physiology and gas density paper.

Simon Mitchell

 

[huwporter]

Thanks for sharing Simon. Although the paper is focused on rebreather diving, it appears the gas density recommendations apply equally to OC?

 

[RainPilot]

Hello

The Rebreathers in Scientific Diving Oroceedings (papers from a joint AAUS / NOAA / DAN / US National Parks Service conference held at Catalina Is in Feb 2015) have just been released today.

https://dl.dropboxusercontent.com/u/22145620/Rebreathers and Scientific Diving Proceedings 2016.pdf

In it (page 66) is a paper on respiratory physiology and diving which contains the first evidence-based guidelines on gas planning to ensure gas density falls within a safe zone. The paper describes the data which justify the limits, and provides a guide to calculating gas density.

The proceedings contain a variety of other papers including one on decompression which discusses the deep stops controversy being debated on a thread in the technical diving forum. Please don't discuss deep stops here.

I am happy to answer any questions related to the respiratory physiology and gas density paper.

Simon Mitchell

What if we talk about deep stops here but don't tell Ross?

 

[C Dub]

Amusing dust-up with Pyle......haha

 

[kelemvor]

Interesting paper for other reasons as well. I wonder if manufacturers such as shearwater will update to meet the alarm recommendation. Currently they don't provide tactile or audible alarms.

 

[Dr Simon Mitchell]

Amusing dust-up with Pyle......haha

Let's not talk about deep stops here. Rich is a good mate. The commentary is self explanatory. We fundamentally agree. What he does is not what we have been discussing on the other thread.

Simon

 

[Dr Simon Mitchell]

Thanks for sharing Simon. Although the paper is focused on rebreather diving, it appears the gas density recommendations apply equally to OC?

Hello,

My recollection is that Gavin has very similar data for OC (I have emailed him to clarify that). You would certainly be on safe ground treating the recommendations as generalisable to OC.

Can I be clear that we are not saying you will inevitably get into trouble if you violate these guidelines because that is demonstrably not true. However, these data are the best and most applicable to our diving so far, and it is clear that there is a significant inflection in risk around 6g / L.

Simon M

 

[Storker]

My recollection is that Gavin has very similar data for OC (I have emailed him to clarify that). You would certainly be on safe ground treating the recommendations as generalisable to OC.

Thanks a lot for that clarification.

 

[kensuf]

Thanks for sharing this.

 

[RainPilot]

Just got done with reading the papers. Very interesting stuff.

I seem to recall a discussion around some videos of guys doing deep CCR diving with the little "cough" at the end of each breath indicating they were pretty close to the edge for gas density without realising. Watching the Shaw footage after that, knowing what I was listening to, was very sobering.

And the deep stop comment was firmly tongue in cheek, I have had enough of that conversation for a lifetime honestly. Seems the mods have too.