Plan second dive using downloaded data from first dive?

[stuartv]

Is there a way to do a dive then download the dive data into Multi-Deco (or V-Planner or an equivalent program), mark that as the 1st dive, set an intended surface interval, and then use the program to plan your second dive?

From what I can figure the only way to really plan a second dive after completing a first one is to use the planning mode on the dive computer (e.g. my Petrel 2) to figure out what my SI, and second dive depth/time plan is. Then I would have to manually calculate the gas requirements based on the plan the dive computer comes up with.

Is there a better way to plan a second dive that factors in actual tissue loading from a previous dive?

 

[ajduplessis]

To my knowledge there is no way of importing/downloading dive data directly into a PC based planner. You can define multi day dives with the appropriate parameters (gasses, depth, time and SI) on v-planner etc. The software will track all the loading etc (simulated, not actual). Thus, if you follow the plan(s) the T, you should have an "accurate" dataset.

The other options is manual calculations, or plan on your DC.

 

[stuartv]

Thanks, AJ. That's the conclusion I had come to. Kind of a bummer. Dive computers don't calculate gas consumption in planning mode (as far as I know) and personal computers don't have a way to account for actual current tissue loading when you plan with them. It seems like it would be really nice if you could do all that planning in one place.

 

[RJP]

Thanks, AJ. That's the conclusion I had come to. Kind of a bummer. Dive computers don't calculate gas consumption in planning mode (as far as I know) and personal computers don't have a way to account for actual current tissue loading when you plan with them. It seems like it would be really nice if you could do all that planning in one place.

Deco theory is the epitome of "Measuring with a laser, marking with chalk, cutting with an axe."

Don't get caught up in looking for false precision here; absent cellular-level nitrogen sensors "actual" tissue loading is "theoretical" tissue loading at best.

Note: you can easily use actual gas consumption from one dive to plan a subsequent dive by changing your SAC/RMV in v-planner or whatever you use.

 

[PfcAJ]

Thanks, AJ. That's the conclusion I had come to. Kind of a bummer. Dive computers don't calculate gas consumption in planning mode (as far as I know) and personal computers don't have a way to account for actual current tissue loading when you plan with them. It seems like it would be really nice if you could do all that planning in one place.

petrel shows estimated gas consumption in planning mode. It's neat.

 

[stuartv]

I will have to check that out! I haven't actually really played with the planning mode on my Petrel.

---------- Post added January 12th, 2016 at 03:22 PM ----------

petrel shows estimated gas consumption in planning mode. It's neat.

I just read the manual on that. It doesn't allow you to enter the surface interval you want to use? It appears to tell you a plan assuming the current tissue loading and that you're getting in the water right now?

That seems not nearly as useful as if you could enter a dive plan and then what-if on SI ("what's my deco if I wait 1 hour before I do this dive? How about if I wait 2 hours?"). It also only lets you enter 1 dive level. Again, not nearly as useful as it could be.

I'm back to wishing Multi-Deco (or V-Planner or whatever) would load a logged dive from my computer and then accept that data as the 1st dive. Then I could set my desired SI and enter my desired 2nd dive and let it tell me a complete deco plan and gas consumption data.

Yes, I realize deco is not an exact science, but I'd rather start a dive with the best guess of a plan that I can. And it seems as though all the data necessary is available. It's just a case of nobody actually developing the necessary software (yet).

 

[taimen]

I'm back to wishing Multi-Deco (or V-Planner or whatever) would load a logged dive from my computer and then accept that data as the 1st dive. Then I could set my desired SI and enter my desired 2nd dive and let it tell me a complete deco plan and gas consumption data.

The planning mode in Subsurface desktop version has exactly this functionality.
Subsurface

I found this old thread while searching dive planner questions, and decided to add.

 

[kensuf]

Jumping in the water and just blindly following your computer is for 30' deep keys diving.

Option 1 - use multi-deco to plan your dive beginning with the first dive of the day, then dive your plan, then use multi-deco to plan your second dive of the day (tell it your SI and it will track your hypothetical inert gas), then dive your plan.

Option 2 - use your petrel to plan your dive beginning with the first dive of the day, then dive your plan, then use your petrel to plan your second dive of the day (it will track your inert gas), then dive your plan.

 

[stuartv]

The planning mode in Subsurface desktop version has exactly this functionality.
Subsurface

I found this old thread while searching dive planner questions, and decided to add.

Right. Thanks for adding this info to the thread for posterity!

When I started this thread, I was still a few months shy of completing my first technical diving certification. Since then, I have done a few tech dives and have a much better handle on planning repetitive deco dives.

And, yes, Subsurface is awesome, including being able to use it for exactly that. It makes it easy to plan a second dive based on the actual (calculated, of course) tissue loading from the first dive, instead of basing it on calculated tissue loading from a theoretical square (or multi-level square) profile.

 

[taimen]

Since then, I have done a few tech dives and have a much better handle on planning repetitive deco dives.

Are there other, prehaps even better software options with this functionality? For me these are currently just learning tools for curiosity, as I still dive stricly in rec limits. Visualization of tissue nitrogen loading during surface interval would be interesting. With Subsurface I just have to fiddle with starting time of the dive plan to see how much residual nitrogen effect there is.