Mandatory Gas Time Alarm at beginning of the dive

[hhouter]

Asked Claude AI to do a check on anomalies for GasTime and Ventilation of this dive:

That chart makes the pattern obvious — GasTime should trend smoothly downward (or oscillate gently as you work harder/easier), but instead it repeatedly stabs down to zero and snaps back. Every one of those spikes lines up with a missing Pressure reading

Pattern summary:
Dropouts are spread across the entire 55-minute dive, not clustered at a specific depth or phase.
Most are brief (1 sample, ~0–10s), but two stand out — 17.8 min (10 samples, ~60s) and 16.0 min (6 samples, ~50s) — nearly a full minute each with no valid gas data. 26.3% of all gas-0 readings are affected.

Is Suunto able to comment on the findings and conclusions from @mikenizm ?

[hhouter]

Did the same for the JSON file from my Buddy who uses the Suunto Ocean and was making the same dive with me that day… These are the reults.

Claude.io: This dive’s data is much cleaner than the previous one.

Here’s what I found:
Dropout rate: 3.6% (much lower)
Only 13 of 360 gas-0 readings have missing Pressure/GasTime, spread across 9 short episodes — 7 are single-sample blips (0-1s), the longest are just 2 samples.

Compare to the earlier dive’s 26.3% dropout with 43 episodes — this transmitter connection was far more stable.

Startup ramp-up (expected, not really an anomaly):
The first ~5 samples show GasTime/Ventilation as None (not 0) while Pressure is already valid — the computer hadn’t accumulated enough breathing data yet to compute a rate. This is normal startup behavior, distinct from the mid-dive zero-dropouts.
Right after that, GasTime hits a flat 6000-minute ceiling for 3 consecutive samples (08:54:19–08:54:39) — an unrealistic 100-hour “time remaining,” clearly a display cap/sentinel value used while the consumption estimate is still very low/unstable, not a real prediction.

A genuine (non-error) exertion spike: Around 08:54:59–08:55:39, Ventilation jumps to ~0.0004–0.00044 (roughly 4 std devs above the dive’s mean of 0.000176) for 5 consecutive samples, and GasTime correspondingly drops sharply (5166 → 4085 min).

This lines up physiologically — harder breathing → faster projected gas depletion — so it looks like a real brief exertion event (current, effort, etc.), not a sensor glitch.

Minor sensor noise:
Pressure “increases” slightly (rather than only decreasing) at 36 points in the dive, but these are tiny — averaging ~13,000 out of readings in the ~7-20 million range (~0.06-0.1%), consistent with normal transmitter/quantization jitter rather than any real gas refill.

No negative values, no NaNs, Ventilation and GasTime otherwise stay in sane ranges (1278–6000 min, 0.000096–0.000442) for the full 57-minute dive.

Bottom line: this dive’s transmitter link was solid — the only real data-quality flags are the brief startup-ramp None/6000-cap period and a handful of tiny pressure-noise blips, nothing like the recurring false zero-outs from the other dive.

[Nandodiver]

Ive being “lucky” so far

Never had any random gas time alarm beginning at the dive , except today when i had 50 bars at the end of the dive… but that is mandatory gas alert at 50 bars

Nautic & Nautic S
6 dives with 2 transmitters and counting

[Nandodiver]

I hope all of you with this bug dive with the analog pressure gauge + transmitter

While i like to use transmitters the SPG is always theres, sidemount or backmount.

[hhouter]

@Nandodiver … just like the SPG we would expect that a device like the Nautic will simply work. You probably don’t question the gauge to be correct, that is what the Nautic should provide also.

[Nandodiver]

@hhouter Just taking a guess… but it possible that the first order/serial of transmitters might be faulty…
My transmitters arrive in 15 july 2026

You should gather an excel with owner data to try to find a common pattern between the transmitters.

[Nandodiver]

date of arrival 15 july 2026

First 2 digits (YY): Year of manufacture
Next 2 digits (WW): Week of the year the device was made.
Remaining digits: Unique factory production numbers

Transmitter Model DP142
Serial 2625xxxxxxx
Serial 2625xxxxxxx

Nautic DW251
software 2.49.32
bluetooth 3.0.50
serial 2553xxxxxxxx

Nautic S DW253
software 2.54.12
bluetooth 3.0.54
Serial 2604xxxxxxxx

[hhouter]

@Nandodiver that might be an option but why is my EON Core on the same POD and same dive where the Nautic logs the alarm not giving any comparable errors? My expectation is that the errors are in the Nautic.

[Nandodiver]

@hhouter do you have the problem in :

Sunnto Tank POD (new version)

Or the

Suunto wireless tank pressure transmitter (old version)

[hhouter]

@Nandodiver I have the tank POD, i believe the transmitter only works with the older computers like Vyper and the D Range of dive watches.
I bought the POD in the beginning of this year and i’m not aware that there is a new version available.

[Nandodiver]

This morning i had 2 x Mandatory gas alarm with both dive computers connect to the same transmitter and completely diferent times

1x Nautic (right arm) (battery 45% )
1x Nautica S (left arm) (battery 18% )
1x transmitter on right side (backmount)

and from my findings i believe is related with bad communication between transmitter and dive computer

Ps: its the first time im using the configuration single gas tank, my normal configuration is multiple gas (even if both tanks are air ) Could be related or not with the alert/bad communication.

pps: this was the dive i had most dropouts (no idea why)

NAUTIC S

Mandatory gas alarm 7m26s
Air consumption 100L/Minute 7m31s
Dropouts time on Nautic S 8m41s + 9m.28s + 26m49s + 27m21s + 29.26s

Theres was some Dropouts that i didn’t record, not sure if was at same time has the Mandatoy gas alarm

NAUTIC

Mandatoy gas alarm 26m28s
Air consumption 100L/Minute 26m28s
Dropouts time on Nautic 9m19s + 26m43s + 27m20s + 29m24s.

[Nandodiver]

More prints

[Nandodiver]

more prints

[Nandodiver]

Here the Nautic S had dropout and i move the arm closer to the transmitter to re-connect

[Nandodiver]

here Nautic & Nautical S had dropout at same time, and i was able to check the air consumption in Nautic

[Nandodiver]

Another dropout Nautic & Nautical S

[Nandodiver]

The following air consumption is not making sense on the Nautic S
Tank 12 L x 197 bar = 2364 bar

start 197 Bar
end 43 Bar
154 Bar x 12L =1848
2.70 ATM x 44 minutes = 118

1848L / 118 =15,6L minute

[hhouter]

@Nandodiver This is why I think, the POD does not have anything to do with it, somewhere in the Ventilation and GasTime calculation as seen by @mikenizm something goes crazy, it is corrected after some time but this is a serious issue to be solved asap!!!

[Nandodiver]

@hhouter the air consumption is definitely a bug (starting new topic about it)

[hhouter]

@Nandodiver Correct, but might also be related to the Ventilation issue…