V-planner or Shearwater

[dave22387]

So I'm coming into the 21st century here. I was raised to run your deco plan on V-planner, write it down a bunch of places, then dive your plan... With a plan and a bottom timer is how I've dove for years.

I've finally decided to come out of the stone age and buy a Shearwater. So here's my question... Do you guys:

A) run a plan using software and have the computer as backup?

B) run the plan using the Shearwater (pre dive) and write that down for backup to the computer and deco via the computers instructions?

C) just do your gas planning and hop in and ride the computer (idk about this one but I'm old school)

It seems B makes sense to me as I'm assuming I can't make the software match the computer so you have to either follow the plan or the Shearwater.

Let me know guys as I want to get the benefits of this incredible piece of technology. If you do something else please let me know.

 

[scubadada]

There are decompression programs that run Buhlmann ZH-L16C with gradient factors, same as the Shearwater computers

 

[dave22387]

Ok so I can make the plan and computer match somewhat. Cool thanks. Now is that what you find most people do?

 

[JohnnyC]

Run the plan in Multi-Deco (ditch the VPM stuff) so you have an idea of run times and gas volumes.

Run lost gas and +/+ plans in Multi-Deco.

Put this information in your wetnotes.

Make sure your Shearwater is the running the same GF as what you made your plans with.

Dive following your computer, with tables as a backup. Your computer is smarter than you. It knows things you don't. It's more accurate. It is your primary source of information. Your tables are in the event that you have a significant computer failure and your backup computer isn't the same as your primary.

 

[DavidFL]

What @JohnnyC said. I have a primary and backup Shearwater, and have a Multi-Deco plan of deco and gas variations in wetnotes. Same algorithm and GFs on all three.

 

[dave22387]

Run the plan in Multi-Deco (ditch the VPM stuff) so you have an idea of run times and gas volumes.

Run lost gas and +/+ plans in Multi-Deco.

Put this information in your wetnotes.

Make sure your Shearwater is the running the same GF as what you made your plans with.

Dive following your computer, with tables as a backup. Your computer is smarter than you. It knows things you don't. It's more accurate. It is your primary source of information. Your tables are in the event that you have a significant computer failure and your backup computer isn't the same as your primary.

I like that and feel comfortable with that. Thanks for the info!

 

[TrimixToo]

I use Multideco for gas planning, and run the dives on my Petrel and Perdix. (Previously, I used my Petrel and VR3.) If either computer fails, I'm calling the dive. Before I had two trimix computers, I used a recreational one as a backup with +/- plans on wet notes. I have only ever seen one computer fail in the water, ever. But if both computers fail, I'm screwed without a reliable depth and time reference no matter how you slice it, and wet notes will not help me. If I find someone (anyone!) willing to loan me a computer and I can guess at the total bottom time reasonably well, I can use a variant of RD to exit without injury (probably), but otherwise I'm going to be guessing based on gas pressures.

 

[KenGordon]

If I am diving OC the slate plan is most important as it was how I figured out I had enough gas. So I must follow the slate for the bottom part of the dive. Then I will be following it for the ascent until the last stop when I might go up when the computer is clear. If the computer is really showing much shallower stops than the plan I might move to the computer earlier, but I will be stopping for gas switches anyway so I might as well stop as planned.

The gas plan, especially how everyone gets to the first gas change in the case of a failure, is what matters. Usually there will be more than ample deco gas unless you choose silly cylinders.

If you just go by the DC deco plan and you suddenly need or have to donate gas then how do you know you will have enough?

 

[dave22387]

If I am diving OC the slate plan is most important as it was how I figured out I had enough gas. So I must follow the slate for the bottom part of the dive. Then I will be following it for the ascent until the last stop when I might go up when the computer is clear. If the computer is really showing much shallower stops than the plan I might move to the computer earlier, but I will be stopping for gas switches anyway so I might as well stop as planned.

The gas plan, especially how everyone gets to the first gas change in the case of a failure, is what matters. Usually there will be more than ample deco gas unless you choose silly cylinders.

If you just go by the DC deco plan and you suddenly need or have to donate gas then how do you know you will have enough?

Very good points. Thanks for the input

 

[DanielRJones]

Have a petrel 2 and a computer running in guage mode (puck pro)

I cut my tables in multideco and write them on my wrist slate / wet notes
Primary
+5m
+5min
+5m +5min
Lost deco

Then i dive to my computer knowing i have the tables as backup. Normally cuts about 3-5mins off my tables.