waterpirate
Contributor
Is anyboby even useing the navy tables for anything but disscussion on SB?
Eric
Eric
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My guess is that doing the 10' stop after teh 20 increases the off gassing rate.
Doesn't V-Planner use VPM? And aren't gradient factors (like 30/85) a Buhlmann thing?
I agree. Ten foot stops are simply an annoyance in open ocean. Plus many people have been doing the 10 foot stop on 100%, so there is little benefit, compared with combining the times in a 20ft stop. The 20ft stop is just as effective, it is done below the 15 ft hang bar, below most of the swells, etc. The 20 ft stop is when most of us go to 100% anyway. Once am on 100%, I am not particularly concerned with additional ongassing.I suspect it has less to do with what's I vogue, and more to do with what works, and is functional.i doubt it has anything to do with fitness standards, or a specific scientific basis. It is just convenience. If a deco program shows me doing a 20 ft stop and a 10 ft stop on 100%, chances are I will combine them at 20 ft. In open ocean, the 20 ft stop makes sense. In other circumstances, the choice of a final depth depends on the environment. If I go to 40 Fathom, and there is a nice platform at 20 ft, where I can doze while doing my 20+ minute stop, without getting in someone's way, that's where I will do my deco. There's a 10 ft platform, too, but there is more traffic.
When a 10 ft stop might make more sense is when there is a limited gas supply concern.
Doesn't V-Planner use VPM? And aren't gradient factors (like 30/85) a Buhlmann thing?
No. It won't. Not on oxygen.
Tissue pressure of N2 is whatever it is.
pN2 in the breathing gas will be zero on 100% O2, no matter what the depth, so the pressure gradient is the same at any depth,so offgassing and hence length of deco stops should be the same.
Doing a final stop on O2 at 10 feet has the advantage that CNS loading will be lower,and less O2 will be used, but the total deco time should be the same.
---------- Post added March 2nd, 2013 at 09:59 AM ----------
Yes and Yes!
Wont you still have residual n2 in the lungs coming from the off gassing process for atleast say 5 min or a good portion of the 10 ft stop time. Not argung , just learning.
I must be dead or bent or toxed then
It's not a universalism IMO. I have not done a 10' stop in 7 years or so on a staged decompression dive. I do 3 (or longer for more significant exposures) minutes up from 20' at the end of a staged decompression dive. O2 clock is planned for.