MOD Stickers

[tbone1004]

@tbone1004 why is the 21/35 above at the equivalent 57 meters if its a deco gas (i.e. 1.4 ppo2) when all the others in the list are at 1.6 ppo2

I believe it's just nominal values to get 21% and I'd have to check the Wakulla cave map but I'm pretty sure I remember hearing something something about that depth profile and there was some convenience thrown in there with the ascent profiles. 21 sounds good because it's the same as air, and that should actually correlate to about 220ft instead of 190ft, but 220 doesn't work for a deco spot.

 

[crofrog]

Gas density of 21/35 is 6.2g/L at 190ft. Which is the absolute maximum gas density recommended by Anthony and Mitchell.

 

[inquis]

@tbone1004 why is the 21/35 above at the equivalent 57 meters if its a deco gas (i.e. 1.4 ppo2) when all the others in the list are at 1.6 ppo2

FWIW, the density at 190 ft/57m is at the current recommended limit of 6.2 g/L (on both CC & OC). I don't know whether that was a consideration when the choice was made, as I don't recall the timelines off the top of my head.

 

[NothingClever]

Provided below is a link to the benchmark article on gas density for any of the doubting Thomases lurking out there.

https://dan.org/alert-diver/article/performance-under-pressure/

Also, to highlight something important from the article:

Enriched-air nitrox with 32 percent oxygen (EANx 32) at 110 fsw and 130 fsw results in densities of 5.6 g/L and 6.54 g/L, respectively, surpassing both recommended and hard limits.

110fsw is 33m so when GUE divers talk about thinning out the soup with He after 30m, let’s not get our knickers in a bunch and accuse GUE of producing elitists.

 

[Heat Miser]

Gas density of 21/35 is 6.2g/L at 190ft. Which is the absolute maximum gas density recommended by Anthony and Mitchell.

makes sense