EFX
Contributor
So I am planning a dive trip weekend. Wanted to see if anyone could help with some off gassing info. I am planning a 2 tank dive with EAN to no more the 80' without getting into deco. Followed by another day of 2 tanks using EAN to 70' or so not getting into deco. Then followed by an early morning dive to 15' MAX but need to be on a plane 12 hrs later. I know the risks but what is a dive to 15' really going to do?
I compared your profile with another profile with the same ending N2 load. I chose dive times that would result in 5 minutes of NDL before ascending. All descending and ascending rates were equal: 60 ft/min descent, 30 ft/min ascend to stop, 20 ft/min stop to surface. All dives were done using Buhlmann ZH-L16 algorithm (16 compartments). Starting pressure at the surface was assumed to be sea level for all dives. For reference, the inspired surface pressure (subtracting out the water vapor pressure in the lungs) at sea level is 24.5 fsw (feet of sea water). Here's what I got using my spreadsheet:
Your profile (all dives on EAN32):
Day 1: 80 ft for 42 min, 15 ft for 3 min, 80 min SI, 80 ft for 40 min, 15 ft. for 3 min.
Day 2: 70 ft for 69 min, 15 ft for 3 min, 80 min SI, 70 ft for 60 min, 15 ft for 3 min.
Day 3: 15 ft for 90 min, 12 hr SI.
After 12 hours compartment 16 had the highest N2 load at 25.4 fsw.
Compartments 1-9 have cleared.
To get the same N2 loading of 25.4 in compartment 16 for one dive on air:
70 ft for 32 min, 15 ft for 3 min, 12 hour SI.
Compartments 1-8 have cleared.
Based on this comparison would you fly out 12 hours after a 32 minute dive to 70 ft on air?
Note: the spreadsheet used a GF-Hi of 100% and does not add conservatism for multiday diving.
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