MultiDeco Integrated Excel Gas Planner

[wachtelcm]

I’m sharing a copy of my MultiDeco integrated Excel gas planner. I want to start by saying I’m not a dive instructor. This calculator is not a substitute for technical dive training. All calculations should be verified for accuracy. It is possible for this calculator to result in an error. Serious injury or death may occur. It is your responsibility to fully understand the calculations in this spreadsheet before using it to plan a dive.

INTRO

This planner can be used in three ways. Tabs inside the spreadsheet are labeled for each type of use.
Tab 1. (Mobile) Copy/Paste data from MultiDeco Android/Apple App into open excel file.
Tab 2. (PC) Copy/Paste data from MultiDeco PC version into open excel file.
Tab 3. (Manual) Manually enter data from any deco planner into the sheet.

NOTE: Make sure if you are using this on a mobile device you are using the mobile device tab and the same with the PC version. PC excel version will only work with the PC MultiDeco and Mobile will only work with the app version because the reports are formatted differently. Most of my testing has been with Android and PC. I believe the Apple phone/MultiDeco integration should work the same.

HOW IT WORKS

At the top of the blank calculations sheet there is an orange cell. Follow these directions step by step. Only enter data into blue cells. Cells that are not blue are locked. Yellow cells are used to highlight where to start pasted text. It is OK to copy data from MultiDeco into yellow cells. They are also not locked.

THEORY

This gas planner is designed to be used for open circuit nitrox and trimix diving with high O2 deco mixes for accelerated decompression.

This planner will assist in preparing a decompression plan with sufficient gas supply to deal with the following deviations from the original plan:

• Increased decompression time resulting from extended time at depth.
• Increased decompression resulting from increased depth. (Depth may not increase depending on the conditions limiting increased depth at the dive site.)
• Increased decompression time resulting from loss of decompressed gas after extended time and increased depth.

All dive plans need to be thoroughly reviewed before using them. This planner should not be used blindly to plan a dive.

INPUT

The following plans copied from MultiDeco (or manually copied from any deco planner)

Plan 1: Actual plan with no contingencies
Plan 2: Actual plan plus contingency depth and/or contingency time.
Plan 3: Actual plan plus contingency depth and/or contingency time with a loss of decompression gas.

The 2nd dive on the lower half of the sheet should be used only when the remaining gas from the first dive is used for a 2nd dive. The starting pressure for the 2nd dive will be the same as the ending pressure for the first dive. This should only be used for projection planning purposes. Actual pressures should be adjusted in a new blank sheet after surfacing from the first dive.

OUTPUTS

Slate – The slate will simplify the data from the three plans. It can be directly copied by hand onto your dive slate or printed and laminated for backup in the event of computer failures.

Graph – The graph will plot depth and gas pressure over time for all three plans. The rule of thirds, turn pressure and rock-bottom pressure should be considered when reviewing the graphical output.

GASES

This gas planner is for open circuit diving only.

This will work with nitrox 21-99% and Trimix (with lower with lower O2%).

If using oxygen as a deco mix, use 99%, not 100%. MultiDeco uses the word “OXYGEN” for 100% O2 in the report and this calculator does not understand what “oxygen” means. The delta between 99% and 100% O2 for decompression is trivial.

The number of cylinders for each mix can be changed as well as SAC rate, gas volume and pressure. You can adjust all of these on the fly.

A total of 3 different mixes can be used. Only the back gas column will recognize trimix. If more than one trimix is used this planner will not work.

WARNINGS

For the first 2 plans, the “total volume used” cells turn from green to red for each plan if contingency volume is exceeded.

On the “loss of deco” plan, the total volume used cell will turn from green to red when the ending pressure is less than 500psi.

The PPO2 cell will change from white to red when the PPO2 for the bottom gas exceeds 1.4 PPO2.

EXAMPLES

There are a few tabs showing example data input. These plans should not be followed and there are some intentional errors to show warnings. Use these plans as examples for how to input data for both the mobile and PC versions.

DEMO VIDEOS

PC Version:
Mobile Version:
I would love to hear some input and continue to improve this planner.

Dive Safe.

-Chris

 

[rjack321]

Multideco already does this for you way easier than copy pasting

 

[wachtelcm]

How do you plan for things like rock bottom gas, dissimilar cylinder sizes or different fill pressures when only using MultiDeco?

 

[Polarorbit]

You seriously need to find a different, and unique, name for your tool.

MultiDeco lets you plan multiple different cylinder sizes and pressures but I think each does have to be a different gas. It hasn’t been a problem since I dive a twin set. The side mount divers I know use matching cylinders for bottom gas. Is it a common practice somewhere to dive mismatched bottom gas cylinders?

 

[wachtelcm]

You seriously need to find a different, and unique, name for your tool.

MultiDeco lets you plan multiple different cylinder sizes and pressures but I think each does have to be a different gas. It hasn’t been a problem since I dive a twin set. The side mount divers I know use matching cylinders for bottom gas. Is it a common practice somewhere to dive mismatched bottom gas cylinders?

Open to new names, any suggestions?

I didn't realize you could do this in the PC version of MultiDeco. Most of my experience has been with the Android version. In retrospect I probably could have skipped integrating that version.

Regarding dissimilar cylinders, I'm not referring to carrying dissimilar cylinders. I'm referring to dive with a buddy who has different size cylinders. Before the dive I often run my buddy's gas against my deco plan as a check. I can do this on my phone.

 

[Polarorbit]

WachtelPlan?

I use the iPhone version and can define multiple cylinders on it. I’ve never used the Android version but it would seem odd for that capability to be different.

Perhaps I’m not getting the issue you’re addressing. You enter your planned depth, bottom time, and gasses and MultiDeco gives you your dive plan and required gas volumes, based on your SAC/RMV. For rock bottom, you add the volume required to get a stressed buddy to the surface. Assuming you’re using the same gasses, wouldn’t you just plan for the diver with the smallest cylinders since that’s the limiting gas volume?

 

[wachtelcm]

WachtelPlan?

I use the iPhone version and can define multiple cylinders on it. I’ve never used the Android version but it would seem odd for that capability to be different.

Perhaps I’m not getting the issue you’re addressing. You enter your planned depth, bottom time, and gasses and MultiDeco gives you your dive plan and required gas volumes, based on your SAC/RMV. For rock bottom, you add the volume required to get a stressed buddy to the surface. Assuming you’re using the same gasses, wouldn’t you just plan for the diver with the smallest cylinders since that’s the limiting gas volume?

I already have something called the Wachtel Plan. LOL.

The backstory on this is when I took ANDP all the calculations were done manually and I also have a lot of experience in excel. I started laying out the calcs in excel and it turned into this. At this point I've become accustom to it. It works for me and I wanted to share it.

I guess its somewhat eye opening that other people aren't running calcs. and only using MultiDeco instead. My output from MD is somewhat different but I guess it get you to the same place. I clearly did thing the hard way.