Question on dislay with deco stops

[mapoubelle]

Hello I tried to better understand what is displayed on the OSTC using the simulator.
I have a few following these simulations. I took some pictures in order to allow a better understanding.

[attachment=2]IMG-2841.jpg[/attachment]
I would expect the TTS to be 1+5+1+3 (30m@ 10m/s)=10 and not 9.. or am i missing something ?

[attachment=1]IMG-2842.jpg[/attachment]
What does the green highlight mean?

[attachment=0]IMG-2843.jpg[/attachment]
Maybe due to simulator mode but I tried to switch a gas which was not configured.
From the display I understand that I selected the gas but not confirmed to change. How can this be done ?

Thanks in advance for your help.
Best regard.

[Clownfish]

Hard to tell about TTS as only 6 and 5 metre stops showing. My OSTC 2 shows all stops, yours seems to show only shallowest two. Fairly close anyway.

Green background means you are shallower than the depth of the deco stop. Need to go closer to the depth. IN this case you are at 16 m and need to be at 9 m. I think the green displays if you are more than 0.5 m deeper than the stop.

Not sure about the change, hard to tell from photo.

PS: Attach much smaller sized photos as took forever to download, then view etc.

[Ralph]

Hi,

regarding picture 2841: you have 2 stops, 1 and 5 minutes, and will need 30m/(10m/min) = 3 minutes for the ascent. This totals to 9 minutes. Where do you exect your extra 1 minute to come from?

Picture 2842: green color stands for an information on something "positive" or a hint to do something. In this case, it prompts you that you can ascent to your next deco stop.

Picture: 2843: you are on O2. You are always in the gas that is shown in the lower left. Anyhow, the O2 seems not be propperly configured redarding change depth, so the OSTC thinks there is a better gas available und subsequently prompts you with a gas change advice (green) and marks the current gas (the O2) in yellow as something you can improve your dive on.


The general color coding is like in a car:

green: for your information,
yellow: you shall know about, but no immediate action required
red: immediate corrective action required

BR
Ralph

[mapoubelle]

Thanks Ralph for your answers ! Below some reactions on these.

regarding picture 2841: you have 2 stops, 1 and 5 minutes, and will need 30m/(10m/min) = 3 minutes for the ascent. This totals to 9 minutes. Where do you exect your extra 1 minute to come from?

From the 1min deco @12m -displayed in big as first stop - obviously I might have missed something.

Picture 2842: green color stands for an information on something "positive" or a hint to do something. In this case, it prompts you that you can ascent to your next deco stop.

Ok, I understand that this is just to indicate that I am in the neighbourhood of the my next deco stop. Correct ?

Picture: 2843: you are on O2. You are always in the gas that is shown in the lower left. Anyhow, the O2 seems not be propperly configured redarding change depth, so the OSTC thinks there is a better gas available und subsequently prompts you with a gas change advice (green) and marks the current gas (the O2) in yellow as something you can improve your dive on.

I am quite troubled on this one. Again this was done in the simulator. I followed following steps: Only one gas (air). At 6m I configured O2 (as if I received it from someone else via Gaslist - More) manually - the deco did not improve and the O2 remained in yellow - I understand that the OSTC keeps proposing air as better alternative. might be something linked to the simulator mode although.
When trying with O2 as disabled gas it seems happy but the deco time does not seem to reduce.

[Ralph]

[quote]regarding picture 2841: you have 2 stops, 1 and 5 minutes, and will need 30m/(10m/min) = 3 minutes for the ascent. This totals to 9 minutes. Where do you exect your extra 1 minute to come from?[/quote]

From the 1min deco @12m -displayed in big as first stop - obviously I might have missed something.

| Uups, i overlooked the 12 meter stop. You are right with your sum. I Need to look into the code again as the way the TTS is calculated in detail changed over the cource of the last years. It may be due to rounding and that the final ascent from 5 meter to surface doesn't get counted in the TTS any more.

[quote]Picture 2842: green color stands for an information on something "positive" or a hint to do something. In this case, it prompts you that you can ascent to your next deco stop.[/quote]

Ok, I understand that this is just to indicate that I am in the neighbourhood of the my next deco stop. Correct ?

| Yepp, correct

[quote]Picture: 2843: you are on O2. You are always in the gas that is shown in the lower left. Anyhow, the O2 seems not be propperly configured redarding change depth, so the OSTC thinks there is a better gas available und subsequently prompts you with a gas change advice (green) and marks the current gas (the O2) in yellow as something you can improve your dive on.[/quote]

I am quite troubled on this one. Again this was done in the simulator. I followed following steps: Only one gas (air). At 6m I configured O2 (as if I received it from someone else via Gaslist - More) manually - the deco did not improve and the O2 remained in yellow - I understand that the OSTC keeps proposing air as better alternative. might be something linked to the simulator mode although.
When trying with O2 as disabled gas it seems happy but the deco time does not seem to reduce.
[/quote]

| Simulator or real dive dosn't matter, the simulator is 100% like how the OSTC behaves in real diving. When you are on the extra gas (aka "gas 6" in older nomenclature) the OSTC doesn't have depth and gas type Information on it. So it can not figure out of this extra gas or the regular gas 1 is better. So you need to set the gas 1 as 'lost' via the Gaslist menu to tell the OSTC that this gas is no option. This touches a point in the programming code that has been worked on lately, but the updates have not been released yet.

| When using O2 from the list of configured gases, look out that its Change depth and type (deco) is set correctly and that your ppO2 margins allow for pure O2 from 6 meters. If there conditiosn are met, the deco calculation will already figure in the use of O2, that's way you get no change in the TTS and stops when you Change as soon as the O2 becomes breathable. Indeed, so will so TTS and stops obligation go up if you do not change...

[gr3yw0lf]

regarding picture 2841: you have 2 stops, 1 and 5 minutes, and will need 30m/(10m/min) = 3 minutes for the ascent. This totals to 9 minutes. Where do you exect your extra 1 minute to come from?

From the 1min deco @12m -displayed in big as first stop - obviously I might have missed something.

| Uups, i overlooked the 12 meter stop. You are right with your sum. I Need to look into the code again as the way the TTS is calculated in detail changed over the cource of the last years. It may be due to rounding and that the final ascent from 5 meter to surface doesn't get counted in the TTS any more.

hm....
nope.

30m -> 1st stop = 2'
1'@12m
1'@6m
5'@5m
tts=9'

but the ascent-time 12m -> 6m ~ 0,5' and 5m -> 0m ~ 0,5' is ignored?

edit:
what's realy irritating me is the last stop @5m. that is very uncommon - in my eyes. maybe you should go through your deco-settings - or maybe post them.....

[mapoubelle]

Thanks Ralph for the detailed info.

For the TTS as I see only 1min delta it could be rounding + if final ascent from 5m is not considered.

Regarding the extra gas (aka "gas 6") I understand that I should configure it first and then mark Gas 1 as lost. This indeed changed the deco time.

Regarding my reference to O2 from the list of configured gases. I should have stated that it is configured but disabled. From the simulation I made, It seems that the OSTC only recalculates the deco time when I mark the main gas as lost. I would have expected that the deco is reduced when selecting this disabled gas directly.. whithout marking the "enabled gas" as lost
If the O2 is marked as available it is considered for the calculation and it there is not change in deco time as already considered as from the beginning.

I would be great to have these elements explained a little more in the manual for a future update.

Br

[Ralph]

So, had a look into the code, it calculates as follows:

2 minutes to go from 30 m to 12 m (1 minute for each 10 meter section begun)
1 minute at 12 m
1 minute at 6 m
5 minutes at 5 m
==
9 minutes

The final ascent does not get counted. Older firmwares calculated 1/2 minute (10 m/min) rounded up to 1 minute, or switched to an ascent speed of 1 m/min and thus would have added 5 minutes. Both is somehow to the extremes. So now TTS is kinda "Time to done with Deco" and it is left to the diver how fast (or better slow) he does the final ascent.

The upcoming 3.08 Firmware will calculate the initial ascent in 1 meter sections, which will give a better rounding and will also solve the instability issue with the depth of the 1st deco stop.

ok with that?
BR
Ralph

[mapoubelle]

Thanks Ralph. Clear explanation. I think it is important to fully understand the figures shown on the divecomputer and how these are calculated
(during a dive cruise I have seen some divers confused between deco time and TTS not really knowing what the computer was telling them )

Seems that gr3yw0lf was correct...

hm....
nope.

30m -> 1st stop = 2'
1'@12m
1'@6m
5'@5m
tts=9'

but the ascent-time 12m -> 6m ~ 0,5' and 5m -> 0m ~ 0,5' is ignored?

--> I understand yes

edit:
what's realy irritating me is the last stop @5m. that is very uncommon - in my eyes. maybe you should go through your deco-settings - or maybe post them.....

Euh yes, this is a setting I have set to have last deco-stop at 5m. It's because my buddy is using a Suunto which uses 5m... I wanted to avoid being 2m higher...
For the gas changes I will make more simulations when the new firmware is out as I understand that there has been some changes on this.

Thanks again for the clarifications.

[gr3yw0lf]

Euh yes, this is a setting I have set to have last deco-stop at 5m. It's because my buddy is using a Suunto which uses 5m... I wanted to avoid being 2m higher...

ah - I see.
btw - it is not a really good idea to take a suunto for deco-dives - except in gauge-mode

[mapoubelle]

yeah... tell my wife.. she finds the Eon Core a "pretty" computer...
On the other hand is is only light deco in the Maldives where you have 5-6min deco max. so not big issue but for sure if you plan deco dives I would not use a Suunto especially as it adds some penalties in an un-tranparent way...

[Ralph]

Well, at least anyone doing deco diving with Suunto computers should make sure she/he understands the function of the fuse in the "fused RGBM" algorithm.

[gr3yw0lf]

Well, at least anyone doing deco diving with Suunto computers should make sure she/he understands the function of the fuse in the "fused RGBM" algorithm.

good advice.....

let me guess: "fused" is short for "confused"?

[Ralph]

No, google a Suunto manual and read the official explanation on what will trigger the fuse and what will happen then.

[gr3yw0lf]

or you read this...
http://ns.suunto.com/pdf/Suunto_Dive_Fu ... 1581487213

but - on the other hand, you also should read this...
https://gue.com/blog/gradient-factors-i ... ops-world/

[Ralph]

...and don't miss the fused RGBM safety feature "algorithm lock"

[gr3yw0lf]

yeah - thats great...
not even they have a "NoFly-time" - they also have a "NoDive-time" (sometimes)