Setpoint value

[LFMarm]

These are some examples for 31 min at 50m with diluent 21/35 and GF 50/60:

Set point	Deco [min]
0.7	146
0.8	126
0.9	113
1	101
1.1	92
1.2	85
1.3	80
1.4	76
1.5	72
1.6	70

 

[BlueTrin]

A small increase in PO2 from 1.3 to 1.4 or 1.5 only removes a few minutes of deco. IMHO it's not worth the increased risk of O2 toxicity.

That seems to be a good point.

I think many of the people I talk to actually flush and run it higher (manually) at the 6m stop.

Being curious about what other people do.

 

[divingx]

That seems to be a good point.

I think many of the people I talk to actually flush and run it higher (manually) at the 6m stop.

Being curious about what other people do.

I still do a O2 flush to check if the cells are limited, then I just keep it at 1.3. It’s a little bit harder to keep at a higher PO2 at 6 meters anyway, especially at the beginning of the stop

 

[lostsheep]

Manually bumping up from your high setpoint on deco is an interesting exercise in how much time it saves you.

Comparing the deco time on my petrel controller to the deco time on my standalone perdix after bumping up p02 convinced me it’s just not worth doing, ymmv.

 

[rjack321]

Manually bumping up from your high setpoint on deco is an interesting exercise in how much time it saves you.

Comparing the deco time on my petrel controller to the deco time on my standalone perdix after bumping up p02 convinced me it’s just not worth doing, ymmv.

This ^^^
I might manually add a little over setpoint but I'm not trying to hold it there to save 4mins or something like that.

 

[rsingler]

I manually bump on deco because SurGF, and I don't do it just to shorten the plan.

If on deep rec dives you're surfacing at a GF99 of 42% (or 27%, or 63%), on every deco dive to GF50/70 you're surfacing at 70%. Therefore, the number of times you actually test Buhlmann is probably only a small fraction of your lifetime dive count. Yet the certainty with which folks choose their gradient factors is fun to listen to.

Never been bent. Don't plan to be. The extra 2-15% lower GF99 on surfacing (from the table above) is an extra buffer beyond what I've chosen as my personal GFHi limit. Every minute at 100% inspired O2 (0% N2) lowers my GF99 about 2%.

To me, it's a risk/benefit thing. If I don't screw up and tox, then I'll take a consistently lower SurGF every time. 66% vs 70% might matter, one day. The higher your personal GFHi limit, the more my theory might apply.

 

[BlueTrin]

I manually bump on deco because SurGF, and I don't do it just to shorten the plan.

If on deep rec dives you're surfacing at a GF99 of 42% (or 27%, or 63%), on every deco dive to GF50/70 you're surfacing at 70%. Therefore, the number of times you actually test Buhlmann is probably only a small fraction of your lifetime dive count. Yet the certainty with which folks choose their gradient factors is fun to listen to.

Never been bent. Don't plan to be. The extra 2-15% lower GF99 on surfacing (from the table above) is an extra buffer beyond what I've chosen as my personal GFHi limit. Every minute at 100% inspired O2 (0% N2) lowers my GF99 about 2%.

To me, it's a risk/benefit thing. If I don't screw up and tox, then I'll take a consistently lower SurGF every time. 66% vs 70% might matter, one day. The higher your personal GFHi limit, the more my theory might apply.

But you could just hang out longer for the same effect?

Are you doing this because you have a max time with that skipper?

 

[Tribal]

I do flush and try to keep a high po2 for the first 10 minutes or so but that’s mainly because I can use the practise, when I’m tiered of doing it manual I get in lazy mode and finish my deco at my high setpoint.

 

[rsingler]

But you could just hang out longer for the same effect?

Yep.

 

[L13]

But you could just hang out longer for the same effect?

Or you could do both and get even more of the effect.