Charlie99
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Just like dive computers --- when you are in the NDL region, no stops are required by VPM, but you can always add them in.ianr33:V-Planner is and always has been VPM. (of slightly different flavors)
If it is not giving any deep stops it is because it is not a deco profile.V-Planner is a great tool for doing sanity checks on recreational dives IF you know what you are doing with it,but dont expect it to give deep stops (or any stops at all!) on NDL dives.
One can artificially force VPM into decompression on many profiles simply by cranking up the conservatism to the highest level. What this is showing you is how adding deep stops to an otherwise NDL dive is adding conservatism/safety factor to your dive.
Going overboard and starting deep stops super early doesn't add conservatism or safety ---- it simply adds to your loading. The VPM reports "offgassing starts at xxx feet". Doing a deep stop before then adds to your loading while not having any benefit. Ascending another 10 to 20' beyond that before the 1st stop is reasonable. Even without a deco program it is very easy to show that stopping at anything deeper than 70% of absolute depth makes no sense ---- when breathing EAN32 your inspired ppN2 is only 68% of the absolute depth (because you are breathing 32% O2, 68% N2). In practice, for recreational depths, a 1st stop of 1/2 of bottom depth is a pretty good approximation.
Running nominally NDL profiles through VPM with very conservative settings will also show you that the optimum deco profile spends more time shallow than deep.
Putting all of the above together has led me to an ascent profile that centers around:
1min @ 40'
2min @ 25'
3min gradual ascent from 20' to 10'.
If I'm very heavily loaded, I'll add some additional time so that my total ascent time is greater than the normal 6 or 7 minutes, but keeping roughly the same shape.
If I'm starting the ascent from greater than 80', then the 40' and 25' stops become 50' and 35'.
I base the ascent on where I have been for the last 10 or 15 minutes. If it's been a multilevel dive where the last 20 minutes have been shallower than 70', as far as the ascent is concerned, the fact that earlier in the dive I was at 130' is not relevant.