PO2 settings for deco diving need to be better

Hey all,

When I set the PO2 for the deco gas on a multi-dive setting, it applies that PO2 to my air gas as well. So for example I want a PO2 of 1.6 for deco and 1.4 for my main gas. However, you set PO2 for deco of 1.6 and my air shows as a MOD of 65.8m which is also a PO2 of 1.6. Now it isn't a problem for a 50m dive with a single deco gas but really, PO2 should be settable at each gas (should be a setting when adding the gas in my opinion) rather than a general app setting so that you can have lower PO2's as you are deeper (more risk) with multiple deco stages. 

Anyone else found this to be a problem or am I doing something wrong? Any work arounds?

Also options to set ascend and descend rates would be nice as everyone has their own preferences for planning a dive but thats not really much of an issue.

Thanks!

Ben

  • I think the same.

    Playing with deco planner the PO2 drives me crazy.

    We would need a clear dedicated PO2 setting for bottom gas and deco gas (also independent of O2 percentage)

  • I have played with the deco planner. Now it seems to me:

    • The generic (Dive setup menu) "Deco PO2" sets the MOD and the gas switch depth.
    • In the "Plan Dive" function, you can also change the PO2 which _overwrites_ the generic PO2 setting for gas switch in the plan. For me, this option should be called "Deco/switch PO2" 

    BTW this confusing terminology was known in the MK1 forum, and there was a promise from Garmin that it will be updated sometimes. 3 years ago
    forums.garmin.com/.../po2-settings

  • Has anybody solved this issue yet? Still cannot set individual PO2 values for bottom gas and deco gas. 

  • No and really it shouldn't. When I posted that, it was before I really understood the need for it but since then I have done deco courses, trimix and my full cave and have a much better understanding of decompression planning (it was 3 years ago!). Essentially, there is no real need for a PO2 on your bottom gas as the calculations of your decompression are based on your PO2 of your deco gases only (so the algorithm knows at what depth you will do your switches onto your deco gases) and no part of the calculations uses the PO2 of your bottom gas as that is simply calculated based on what depth you go to on your bottom gas in real-time. You should also plan your dive to a MOD you want and not go beyond it. 

    Sure, it would be nice to see the MOD of your bottom gas at 1.4 for reference when doing a plan/setting up the computer but you can simply have your PO2 shown on your watch face and monitor it in real time during the dive + you should be planning for a max depth within your comfort zone. 

    So I understand why they don't have a PO2 setting for bottom gas and I understand why you may want to see it, but they won't do it as it adds a layer of unnecessary complexity and could be mixed up/misused by someone which may give them different calculations to what they planned.