MultiDeco v4.20

[MultiDeco]

New version 4.20 for the PC, Mac and Linux program is ready now.

A new feature on all desktop platforms, is the ability in CCR plans, to set a fixed set point change in ascent. Typically your deco starts at some approximate fixed distance from the bottom, what ever your plan preferences might be. And if you like to adjust set point at the start of deco then this new setting is for you:

Enter your bottom segment as usual, then a negative depth offset to make the new change

(depths are meters)

Here is a dive to 90m, with SP 1.2, and at 60m the SP will go up to 1.5. The benefit here is the -30m can be left in place and used with any dive:
90, 30, 10/50, 1.2
-30, 0, 10/50, 1.5

or

75, 30, 10/50, 1.2
-30, 0, 10/50, 1.5 << swaps SP at 45m

or

60, 20, 10/50, 1.2
-30, 0, 10/50, 1.5 << swaps SP at 30m


These can also be chained together for a sequence of SP (or mix) changes, all based from the bottom depth.
-30, 0, 10/50, 1.5
-20, 0, 10/50, 1.6

************

Mac updates:

The Intel version of MacOS had a bug in the Moreless plans, that caused a crash - this has been fixed now.


Download from: MultiDeco ZHL-GF & VPM & VPM-B & VPM-B/E dive decompression software for technical divers

 

[LFMarm]

Is it common practice to raise the pO2 setpoint during ascent? Not trying to criticizing in any way this additional feature, just curious as I have never done it and I may learn something new.

 

[Mobulai]

Is it common practice to raise the pO2 setpoint during ascent? Not trying to criticizing in any way this additional feature, just curious as I have never done it and I may learn something new.

As a noob I’d say NONO, but I was only dealing with very short deco during the brief set of CCR dives I did so the difference wasn’t really “necessary”

But it would make sense to transition from the “bottom” ppo2 to “deco” ppo2 as well
Raising the max 1.2>1.4 is how I was trained, so kinda make sense to start gradually raising it in such context; OP is demonstrating a trimix dive so obviously deco obligation is much higher there so why stay longer

 

[Tracy]

Is it common practice to raise the pO2 setpoint during ascent? Not trying to criticizing in any way this additional feature, just curious as I have never done it and I may learn something new.

Probably half and half. I don't, many people I dive with do.

 

[macado]

I know quite a few people who might run a higher ppO2 on deco and less of a ppO2 on the bottom, working portion of the dive.

How much difference deco it makes largely depends on the dive profile obviously. In a lot of cases the difference is quite negligible especially on recreational profiles or even minimal deco profiles.

You'd have to run some profiles and see if it helps you. Also be aware you'll burn up your CNS clock more rapidly (if you care about that..). I'm not going to debate the CNS clock here as that horse has been beaten to death already.

A specific example: 300ft at 25 minutes at 1.2ppO2 for example with GF 50/80 gives you a runtime of 181 minutes (~3 hours) and 83.8% CNS. If you were to bump your ppO2 to 1.4 at 100ft it shaves ~20 minutes off your deco with a runtime of 162 minute and CNS 93.8% Is 20 minutes worth it to you? Maybe, maybe not?

There are also plenty of people who might run a 1.0 ppO2 on the bottom/working portion of the dive to limit oxygen exposure at depth and then they may ramp up ppO2 on deco on the resting portion of the dive.

 

[GF99/99]

Is it common practice to raise the pO2 setpoint during ascent? Not trying to criticizing in any way this additional feature, just curious as I have never done it and I may learn something new.

For deep dives its makes a big difference in your deco obligation.

For sub 150m dives I always like to run 1.0 SP on the bottom phase (yes I know this is low and some may criticize me for this but this my diving style and it works for me, reasons I run 1.0 is at 16atm+ especially when you start getting into the 200m+ rage it does not take much to "spike" your PPo2 so I want to have that extra padding remember if your diving a MCCR at this depth if your not running a needle valve on a non blocked first stage your diving fully manual so giving a little to much on the MAV will get you up to 2.0 real quick. And on an ECCR with a radial scrubber your solenoid can do some interesting things at those depths. Also 1.0 is what your calibrate your unit at) But you can imagine if you just dove at 1.0 for the entire dive your deco obligation would be insane so you have to bump your Po2 up as you shallow up. I actually do 2-3 SP switches for dives like this. Once I leave the bottom phase I will edit my SP on the fly as I'm ascended, usually bump it up to 1.2 or 1.3 then when I get to around 18m I will bump it up to 1.4. Depending on the dive profile Ill bump up to 1.5/1.6 at 6m but not very often, usually my dives are so long bumping up to 1.5 or 1.6 really gets your CNS up there quick and you really don't knock any deco off (If you run a 6hr sub 150m dive the difference between switching to 1.6 at 9m and running that for the rest of your deco or staying at 1.4 is like 4-5min of deco extra but your CNS is probably getting close to 300% where as at 1.4 your probably around 200%)

With the previous version of multideo I use to just fudge in a level put 0 for time time and just input a different setpoint so the software would recognize a SP switch.

 

[GF99/99]

New version 4.20 for the PC, Mac and Linux program is ready now.

A new feature on all desktop platforms, is the ability in CCR plans, to set a fixed set point change in ascent. Typically your deco starts at some approximate fixed distance from the bottom, what ever your plan preferences might be. And if you like to adjust set point at the start of deco then this new setting is for you:

Enter your bottom segment as usual, then a negative depth offset to make the new change

(depths are meters)

Here is a dive to 90m, with SP 1.2, and at 60m the SP will go up to 1.5. The benefit here is the -30m can be left in place and used with any dive:
90, 30, 10/50, 1.2
-30, 0, 10/50, 1.5

or

75, 30, 10/50, 1.2
-30, 0, 10/50, 1.5 << swaps SP at 45m

or

60, 20, 10/50, 1.2
-30, 0, 10/50, 1.5 << swaps SP at 30m


These can also be chained together for a sequence of SP (or mix) changes, all based from the bottom depth.
-30, 0, 10/50, 1.5
-20, 0, 10/50, 1.6

************

Mac updates:

The Intel version of MacOS had a bug in the Moreless plans, that caused a crash - this has been fixed now.


Download from: MultiDeco ZHL-GF & VPM & VPM-B & VPM-B/E dive decompression software for technical divers

Not trying to criticize just wonder for my own curiosity.

With the previous version I just use to add a level with 0 time (same as the example) and the SP switch (same as the example) but I would just input the depth at 60m (not -30m)
So for the example given I would just write that in the previous version
90, 30, 10/50, 1.2
60, 0, 10/50, 1.5

Am I missing something or is this not the exact same thing that the previous version did with the exact same amount in input work. As in you still have to create a level, input a depth, time, mix, and SP. Only difference is inputting -30 or 60 for the depth