Retroactive gradient factor/tissue saturation calculation

[dmaziuk]

... I was thinking of creating spoofed log files and feeding them to Subsurface, but that seems quite difficult.

Subsurface uses an XML file with dives coded like

<dive date='2010-12-05' time='05:08:00' duration='41:40 min'>
...
     <sample time='0:20 min' depth='2.1 m' />
     <sample time='0:40 min' depth='3.3 m' />
...
</dive>

I haven't tried it, but I'm fairly sure it'll work if you just stick your own "sample" lines in the proper place in an existing subsurface log file.

I.e. it shouldn't be that difficult, just tedious.

 

[rjack321]

Playing around with it a little in Subsurface/Decoplanner, it looks like 39m/40 mins

Isn't the pragmatized ascent more like:

130 - 40
70 - 3
60 - 3
50 - 3
40 - 3
30 - 3
20 - 15

Not including the 'slow up' from 20, that gives me a SurfGF of 101 at the end of the 20 foot stop.

Apologies if I'm not understanding correctly, but this is basically what I'm trying to understand - at the edges of the T1 RD envelope (and I think 130 feet/40 mins is the edge of the envelope!), how does a RD profile compare for decompression stress to a 30/85 Buhlmann ascent (pragmatized and non-pragmatized). That's it - not trying to argue whatsoever about the merits of different gradient factors or models or prove that ratio deco is in some way broken.

You'd have to ask someone with a recent T1 cert. Around here the "equal" 70-30ft stop approach is called "linear" and the 1min 70ft etc up to a guesstimated surfacing curve is called "pragmatic". At least that's what my occasional GUE buddies call it. My RD background and terminology is much more dated, back when I was in T1 we were still doing S curves to accommodate the "oxygen window". *eyeroll*

Times have changed and so have terms.
Rough RD eras:
mid 2000s~2010 = S-curves
2010-2018 = linear
20018- now = pragmatic