TTS is adding Safety Stop (3')

[Raf]

Hello,

After an upgrade to the latest firmware i noticed that the TTS is alwyas 3' more.
I have disabled the safety stop (3' on 3m), but i think that the TTS stil adding this.
Is this normal?
Can this be a TTS without the safety stops included.

[Ralph]

Hi,

the extra 3 mins do not result from a safety stop, but from a reduced ascent speed of 1 m/min for the final ascent. So if last stop is set to be at 3 meters, there will be 3 minutes added. This will mount up to 6 minutes with a last stop at 6 meters. That was introduced along with the gas needs calculation to add some safety margin on the figures. As the tissue saturations peak on the final meters to the surface, it's wise to slow down and take these extra minutes on the final ascent.

Ralph

[heinrichsweikamp]

We get this question often with the current version.

What do others think? Should we remove the extra minutes from the displayed TTS?

regards,
Matthias

[Kehrmaschine]

I am not disturbed by this. Ascending to the surface from the last stop with 1 m/min is a good thing. It gives you a realistic TTS anyway. If you want to go faster for any reason, you have some spare time. I wouldn‘t change it.

[algo]

I also think this is a valuable information and reminds you, that a slower final ascend to the surface is better. So i would leave it like it is.

(And if you get a lot of questions about this, it also means that people realize it and don’t unterstand it , but start thinking about this)

[Clownfish]

I think there is no need to add more than one minute to TTS for ascent from 5 metres. Sure, you should take more, but it just causes confusion when it is 5 minutes.

[U-96]

Hi all

Since I dive with an OSTCplus I'm always the guy with the highest TTS value.

I don't see really an advantage in this behavior. During the dive, in my mind I often subtract 2' of the TTS to have an equivalent TTS like my bodys computer. Furthermore, after the deco the TTS value goes immediately down from 4' to 0' and there is no count down running.

Michi
OSTC 2C 7452
OSTCplus 17296

[ClaudeDive]

Hi Matthias and Ralph,
To adjust this point, I think that it may be necessary to have a setting of 1 to 3 m / min of the ascent rate of the last deco stop,

[Rob]

Hi Ralph,
hi Matthias,

according to the fact that it is much more healthy to reduce the speed in the last meters before surfacing, it is a good reminder for those pepole who are not so deep in decompression theory.

I held a CMAS** course (we teach 1m/min during the last 5 meters) and the divers with ostc told me that it is a good idea to be reminded to the slow ascent.
The one with ostc and the latest firmware was the one who didn't forget to slow down.

So, from my point to view - well done. Let it as it is.
The reality proofs that this is a good idea.

And for those who are not interested in slowing down, come on, three minutes at a depth of 3-2-1 m - who really cares.

Regards
Rob

[Arno]

Leave it as it is, the added benefit of a slow ascent during the last 3 meters outweighs the fact that a faster ascent is possible.

If need be than add a setting so those who are really annoyed by it can turn it off, but then again those people count with maybe 10m/minute and they can do the math themselves if they are on 20 meters with no deco obligation. And with deco obligation it's even more beneficial to slow down and those extra 3 minutes really don't matter a lot anymore.

[Ralph]

Hi all,

thanks a lot for your answers and especially the reasonings behind. Due to the works that have currently been done (and will ship with the next beta to come), the TTS itself will not include extra minutes for a slowed final ascent any more. But providing some means to remind divers to take it slow did convince me to be some favourable thing to have. I'll probably write some code that will write a "slow" reminder at the place were otherwise the NDL 240' will appear after the last deco stop has cleared. I hope that will serve all the thoughts you shared with us.

best regards
Ralph

[Clownfish]

Ralph, sounds great.

[ClaudeDive]

Yes, Ralph,

Perfect you could use "Slow I" (Slow with the little arrow up, sur un fond jaune) to remind the diver to slow down from the last deco stop to surface (the same little arrow you used for gas "Work" but to the surface)

Best Regards,

[Ralph]

You mean like this?

Ralph

[ClaudeDive]

Yes Ralph perfect! That's so clear,X(
Best regards,

[dadefay]

Hi guys,

The last Ralph's proposal seems the best solution, along with an updated user manual given the number of improvements and changes ! Otherwise, the forum will be deluged with questions !

Kind regards.

[Ralph]

Hi Didier,

thanks for your point. We'll try to make the release note as comprehensive as possible. There is so much functionality in the Firmware, it is impossible to put everything in the printed manual. We counsel everyone to play a lot with the dive simulator, including doing nasty things like violating stops, choosing wired gases and so on, to learn what the OSTC will do.

save diving,
Ralph

[heinrichsweikamp]

Hi,

The manual will get an update, of course. And for the stable I might tweak the default values (Extended Stops, Gas Change time) a bit to be similar with the last stable.

regards,
Matthias