OSTC3 - Gas type one additional choice “1st+deco”or better changed in "TravelDeco"

[ClaudeDive]

In OC Gas setup > OC Gas List > Edit Gas > Type : we have several choice like "First" "Travel" "Deco"
For hypoxic dives we use for descent "First" gas that we will also use as deco gas,
Eg a dive with Tx 12/58 - Tx 18/42 - Nx 50 - O²
Our First Gas is G1=Tx 18/42 then Travel G2=Tx 12/58 Finally Déco G3=Tx 18/42 - G4=Nx 50 - G5=O²
Currently with OSTC3 we are required to select twice Tx 18/42 for G1 and G3
It would be possible to create one additional choice “1st+deco” (“1er+déco” French) so that the gas first “1st+deco” can in this case take part in the deco and thus avoid to be selected 2 times what will make it possible to leave a free G5 gas to program a feasible gas BO,
"TravelDeco" See my following messages below and the justification, I think that it would better to change the term “1st + deco” by “TravelDeco”.
Regards.

[kaheksa]

OSTC 2 has only "First" gas or not and it goes a little weird calculating TTS in plan and on the dive when using travel gasses. A little change in code would be nice

[heinrichsweikamp]

"Travel gases" are not included in the OSTC currently (As you found out). We have included this in the DRx/DR5 recently and this makes the gas setup a quite complex task. This may or not may be added to the OSTC2 and 3 at some time in the future.

regards,
Matthias

[kaheksa]

130m divecomputer with no travel gases?

How do you suggest setting up the computer then for deeper dives with travel gases do get some point out of it?

[heinrichsweikamp]

Just setup your Travel gas as a normal gas with no change depth and select it the OSTC when you made your gas change.

Example:

G1: *Air 0m <- For descent and buoyancy
G2: TX10/70 0m <- Your Travel/Bottom gas
G3: 50/25 20m <- Decogas 1
G4: O2 6m <- Decogas 2
G5: Disabled

Decoplan will take all gases into account after selecting your 10/70.

regards,
Matthias

[ClaudeDive]

Matthias,
I take again your example: (my 1st example was also good).
For a Hypoxic diving, I will not take air which will be useful to me only for the beginning of the descent,
I will do thus setup my gases with your example:
- G1: Tx 50/25 "First gas" > for descent > -20m > I think that the term "First gas" is not correct in deep diving because we usually use "travel gas" for descent, it would be well to replace "First gas" by “Travel gas” (in French also “Travel gas”).
"Travel gas" in fact the gas enables to descent for then use the "bottom gas" for the bottom,
"Travel gas" it's not the gas that we use on the bottom in hypoxic diving and for normoxic diving we use directly the "Bottom gas" without never the "Travel gas".
Currently in OSTC3 "Travel gas" term is equivocal we don't know if it use at the descent, on the bottom or the Twice.
- G2: Tx 10/70 > "Travel gas" > I think that the term of "Travel gas" is not correct in deep diving because we usually use "Bottom gas" for the bottom, it would be well to replace “Travel gas” by “Bottom gas” (“Fond” in French).
- G3: Tx 50/25 > Decogas 1,
- G4: 02 > Decogas 2,
while waiting for one day, I hope, and avoid to select 2 times Tx 50/25 of your example and to answer my 1st question and it will be well it to keep free G4 and G5 gas to setup has two feasible gas BO, if you create one additional choice “TravelDeco” (in French also “TravelDeco”) so that the gas first “TravelDeco” can in this case take part in the descent and in the deco with only one setting, it would be a good advantage!
This additional choice "TravelDeco" would be of course in additional with current choices "Travel" (ex First), "Bottom" (ex Travel), "Deco" and "Disabled".

[kaheksa]

The computer wont let you activate 10/70 as a "deco - gas 0m" because its hypoxic and if you activate it as "first" then it wont activate "Air change 0m". If you but it at any other depth it will be considered as a deco gas and will mess with your TTS and deco schedule.

All of this means that you cant use the computer for diving over 70m with hypoxic mixes and can only use it as a bottomtimer and dive a plan

[ClaudeDive]

Hi Kaheksa
you must read my message correctly!
I wrote: (with the example give in Matthias's message).
G1: Tx 50/25 for 0m to -20m the descent = "Travel" (In French also "Travel") > it's normonic gas. (With setting: change depth 0m).
G2: Tx 10/70 for the bottom = "Bottom" ("Fond" French) > It's hypoxic Gas for the bottom.
G3: Tx 50/25 for the deco = "Deco" (In French also "Deco") > It's deco gas. (With setting: change depth 21m or 18m).
G4: O2 for the deco = "Deco" (In French also "deco") > It's deco gas.(With setting: change depth 6m).
I do not speak about use G2 to the descent!
I say for the descent with G1 an normoxic gas.
I hope it's clear for you?
Of course you can use OSTC3 over 70m to 120m for the déco IF YOU PUT SETTING CORRECTLY.
With Mattias's example I suggested simply to create an additional choice "TravelDeco" would be of course in additional with current choices "Travel" (ex First), "Bottom" (ex Travel), "Deco" and "Disable".
This new choice would avoid to select 2 times G1 and G3:Tx 50/25 and it will be well it to keep free G4 and G5 gas to setup has two feasible gas BO for an potential backup, what appears to me to be an advantage.
Regards.

[heinrichsweikamp]

Hi,

kaheksa Wrote:
> activate it as "first" then it wont activate "Air
> change 0m". If you but it at any other depth it
> will be considered as a deco gas and will mess
> with your TTS and deco schedule.

No. It's shown greyed-out because it's a 0m gas but not the "First" gas. You can selected it no problems whatsoever.

> All of this means that you cant use the computer
> for diving over 70m with hypoxic mixes and can
> only use it as a bottomtimer and dive a plan

You can surely use it the way I described it, just give it a try in the simulator and you'll see.

regards,
Matthias

[kaheksa]

If I but Air as the first gas then it wont use 10/70 in the simulator and if you but 10/70 as the first gas then it wont use Air with "calculate deco" in the simulator.

We need a option of telling the computer that the gas change is on the descent not ascent

Im using the 2.80 firmware

[heinrichsweikamp]

kaheksa Wrote:
-------------------------------------------------------
> If I but Air as the first gas then it wont use
> 10/70 in the simulator and if you but 10/70 as the
> first gas then it wont use Air with "calculate
> deco" in the simulator.

I asume you talk about the "Planner", not the real-time divemode simulator: Yes, that's true. Such dives can not be planned with the internal simulator. For dives this complex I'd recommend a PC or mobile-based planning tool nevertheless (Like "Multideco" ).

Regards,
Matthias