OSTC Sport set up for sidemount

OSTC's running hwOS sport or tech
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drakcheslav
Posts: 12
Joined: Tuesday 9. June 2020, 15:48

OSTC Sport set up for sidemount

Post by drakcheslav »

I was wondering how to correctly set up the Sport for sidemount.

I'm guessing that I need to set up two gas set ups as two different tanks, and then mark that I've changed gas when swapping tanks.

Is there a different way of doing this or would this be recommend one?
swissdiving
Posts: 735
Joined: Saturday 30. July 2011, 07:30

Re: OSTC Sport set up for sidemount

Post by swissdiving »

Do you have different gases in the tanks?
I would have thought not.

Although, I am not using the Sport, I don't really see why you would want to set up two "different" gasses and swap between them on the ostc when you swap between the tanks. It doesn't make a difference to the deko calculation and just increases the task load. (And of course you would have to do the same on the backup computer...)

Keep it simple.
Cheers,

Hansjoerg

--> 2N ¦ 2201 / 3892
--> OSTC4 ¦ 257 / 392 / 424 / 647 Fischer

RTFM
Ralph
Posts: 657
Joined: Saturday 24. June 2017, 11:31

Re: OSTC Sport set up for sidemount

Post by Ralph »

Hi,

assuming you are using the same gas in both tanks:

you can either set up one tank on the OSTC representing BOTH of the real tanks, set the size of the tank to the combined size of the real tanks.
Or you can set up two tanks in the OSTC, both with the size of the corresponding real tank, set same change depths, set one of the tanks to 'first' and the other to 'work' and activate 'Swap on empty' in Main Menu > Dive/Deco Setup > SAC Setup. Together with Calc.Gas = yes (the 1st menu entry) the OSTC will now chain both tanks, i.e. it won't warn on running out of gas when the 1st tank is calculated to become empty at the end of the ascent, but rather then swaps to the other tank and only warns if this one becomes empty, too.

"Swap on empty" actually chains all tanks, nice feature especially for CCR divers who are always a little bit short on B/O gases: with this option activated, the OSTC will calculate a deco "eating up all gases available", i.e. when the O2 is calculated to be running out, the OSTC then switches to the next 2nd best gas (among all the other deco and dil gases) that is calculated to still have some remains, and so on.

BR
Ralph
drakcheslav
Posts: 12
Joined: Tuesday 9. June 2020, 15:48

Re: OSTC Sport set up for sidemount

Post by drakcheslav »

Awesome reply. Thanks.

One question,
If I set to dive with 2x10, which is 20l.
How to calc the air consumption in subsurface at the end if I have a tank with 100bar left and with 80bar left?

Is the calculation then from 200bar down to an average 90bar or something else?
swissdiving
Posts: 735
Joined: Saturday 30. July 2011, 07:30

Re: OSTC Sport set up for sidemount

Post by swissdiving »

Actually from a cave diving point of view at the end of the dive you should have roughly the same amount in both tanks. However in your case add it up and divide by two.Just treat it as one tank. With doubles BM its as if you had one tank anyway.(unless you dive with the bridge closed). Your SM instructor should have covered this topic...
Cheers,

Hansjoerg

--> 2N ¦ 2201 / 3892
--> OSTC4 ¦ 257 / 392 / 424 / 647 Fischer

RTFM
drakcheslav
Posts: 12
Joined: Tuesday 9. June 2020, 15:48

Re: OSTC Sport set up for sidemount

Post by drakcheslav »

I'm starting my sidemount course next week. I'm just completing my gear.

I read up as much online as I can on sidemount before my instructor comes back and we start the course.
jb2cool
Posts: 111
Joined: Tuesday 21. January 2014, 21:19

Re: OSTC Sport set up for sidemount

Post by jb2cool »

For dive logging software like Subsurface then switching the computer when you switch regs will provide more information and give you more accurate gas consumption graphs in the software. If you are not so interested in the logging then just view these as one large cylinder and it'll save you time and effort switching the computer.
swissdiving
Posts: 735
Joined: Saturday 30. July 2011, 07:30

Re: OSTC Sport set up for sidemount

Post by swissdiving »

If you are just starting SM keep the task load low. You can always experiment later when you're proficient.
Cheers,

Hansjoerg

--> 2N ¦ 2201 / 3892
--> OSTC4 ¦ 257 / 392 / 424 / 647 Fischer

RTFM
drakcheslav
Posts: 12
Joined: Tuesday 9. June 2020, 15:48

Re: OSTC Sport set up for sidemount

Post by drakcheslav »

Thaks,
That's the plan.

I was initially planning on going backmount, but my back problems pushed me to first start SM, then go onto Tec classes.
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