vey interesting article by simon mitchell

[lermontov]

 

[respublica]

Very interesting indeed. Thank you for sharing.
I do not feel confortable at all with the accident video though.

 

[Storker]

Dr. Mitchell's data on gas density and its effect on CO2 retention is interesting, even for OC no-stop diving. According to the graph shown at 46:30, breathing a gas with a density above ~6 g/L carries a significantly increased risk of excessive CO2 retention. Some rather simple math shows us that ordinary air reaches a density of 6 g/L at a depth between 36 and 37m (120'), which is generally regarded as being within recreational limits on air by most agencies. Same thing for standard recreational EAN mixes like 28% or 32%. So, putting some He in your mix when you go below 30m/100' seems to be prudent even for those who don't believe they're narked at those depths.

And also rather interestingly - for me, at least - common normoxic trimixes like 21/35 or 18/45 reach ~6 g/L gas density at practically the same depth as they reach 1.4 bar pPO2.

 

[dreamdive]

Dr. Mitchell's data on gas density and its effect on CO2 retention is interesting, even for OC no-stop diving. According to the graph shown at 46:30, breathing a gas with a density above ~6 g/L carries a significantly increased risk of excessive CO2 retention. Some rather simple math shows us that ordinary air reaches a density of 6 g/L at a depth between 36 and 37m (120'), which is generally regarded as being within recreational limits on air by most agencies. Same thing for standard recreational EAN mixes like 28% or 32%. So, putting some He in your mix when you go below 30m/100' seems to be prudent even for those who don't believe they're narked at those depths.

And also rather interestingly - for me, at least - common normoxic trimixes like 21/35 or 18/45 reach ~6 g/L gas density at practically the same depth as they reach 1.4 bar pPO2.

That is why I don't solely consider equivalent nitrogen values but account for gas density! Especially on dives that will carry a higher work load - I will add more helium.

 

[Kevrumbo]

That is why I don't solely consider equivalent nitrogen values but account for gas density! Especially on dives that will carry a higher work load - I will add more helium.

And a scooter for mobility/locomotion as needed!