[PATCH 2/2] Ticket #831 Fix

[Davide DB]

On Mon, Mar 9, 2015 at 9:42 PM, Dirk Hohndel <dirk at hohndel.org> wrote:
>
>
> If this is actually a show stopper for you guys, then I'll try to get in a
> hack so you can use the software, but a real solution will likely take a
> little longer.

No problem at all, I can live with them.

In the last few weeks I read so many times that usually people get
everything right (mixes, tanks, gas changes) from their dive computers
that I'm becoming feeling a bit outlier. Hence I'm trying to
understand if, regardless of each his own convictions, there is still
room for DIR/GUE/UTD Subsurface users :)

Regarding the gas change 0 at 0 it's a common scenario in advanced dives
or dive locations having to switch to a particular mix on the surface:

* I dive with a pscr rebreather and a hypoxic back gas so I have to
reach a safe depth prior to change to back gas.
* I dive oc/pscr with a hypoxic mix and my dive location (cave or even
reef) doesn't permit to reach immediately a safe depth.
* I dive in a cave where gas mixes are chosen on the cave profile:
first part on mix1 then mix2 and again mix2...

> The question to ask the bug submitter is "why do you want to add a gas
> change at 0'/0:00? -- is this to correct the first gas used?"
> Why? Enter your first gas as first tank. Voila.

What is the main gas and the main tank in the above examples?
By default we tend to consider our main gas the back gas and I set it
as default tank into Subsurface preference dialog then I describe my
dive through the gas change events.
In my above example:

I made a formal gas change at the surface switching to a 35/25
At 30m I switched to my bottom mix: 16/60 on a AL80 [**]
Deco was performed on 35/25, 50/20 and 100%
My backgas was a D8,5L on 16/60 (that is set as default tank in
Subsurface). It's my bailout reserve, my main tank.

[**] I could have more f this.

Should I remove the default cylinder to be able to switch at 0 at 0?
If I had a proper DC managing all of this and I forget to press a
button, could I fix all of this later? Hummm....

PS
My crappy XDeep BT adds its own oddity: it exports via UDDF an unknown
cylinder with real air...

Thank you in advance

-- 
Davide
https://vimeo.com/bocio/videos