Mandatory Gas Time Alarm at beginning of the dive

MartinPadiPro

MartinPadiPro said:

@hhouter damn. I got a email from Suunto with standard answers. Check tank check pod i all did that. It is a wide problem under more Nautic users. Monday i go diving again if the problem is coming back i go send the data to Suunto and let you guys know

Dear Martin,

Thank you for contacting Suunto Support and for sharing the detailed information about the issue you experienced during your dives.

We understand your concern, especially when the dive computer shows a low gas alarm despite having sufficient tank pressure. We will be happy to help you investigate this further.

When a Suunto dive computer triggers an unexpected low gas alarm or the Gas Time value resets despite having enough tank pressure, it is usually related to one of the following factors:

Tank Size Configuration

Gas time is calculated dynamically based on your current depth, tank pressure, and breathing rate (Surface Air Consumption / SAC).

Please check:

Go to Gases > Edit Gas

Confirm that the Tank Size (Volume) is correctly configured

If the tank size is incorrect or missing, the gas time calculation may become inaccurate.

Initial SAC Calculation Phase

During the first 5–10 minutes of a dive, the algorithm calculates your breathing rate. A higher breathing rate or sudden depth changes during descent may temporarily reduce the estimated gas time, which can trigger an alarm before the calculation stabilizes.

Gas Time / Pressure Alarm Settings

Please verify your alarm settings:

Go to Dive Settings > Alarms

Check your configured pressure and remaining gas time alarm thresholds

The default mandatory tank pressure alarm is set to 50 bar, but custom alarm values may affect when notifications appear.

Temporary Tank POD Signal Reconnection

If the wireless connection between the Tank POD and dive computer is interrupted temporarily, the pressure reading may briefly disappear and then update once the connection is restored. This recalculation can appear as a sudden reset of the Gas Time value.

Before your next dive, we recommend checking the following:

Connect both dive computers to the Suunto App and ensure they have the latest firmware installed.

Confirm the Tank POD is correctly paired and the pressure reading matches your mechanical pressure gauge before entering the water.

Ensure the Tank POD battery and connection are functioning correctly.

As a standard safety precaution, please continue relying on your mechanical pressure gauge if any wireless pressure readings appear inconsistent.

After your next dive, if the issue occurs again, please sync both devices with the Suunto App and provide us with:

Dive computer model(s)

Firmware version(s)

Approximate dive time when the alarm occurred

Any screenshots or dive logs available

We will review the information and assist you further.

Thank you for your cooperation.

Best regards,
Zack
Suunto Support Team

MartinPadiPro

https://photos.app.goo.gl/1o43GWsetjia3SfN9

https://photos.app.goo.gl/zhhZfuxBsEteLWo1A

This are mine screenshots

hhouter

@MartinPadiPro said:

During the first 5–10 minutes of a dive, the algorithm calculates your breathing rate. A higher breathing rate or sudden depth changes during descent may temporarily reduce the estimated gas time, which can trigger an alarm before the calculation stabilizes.

Interesting… but that is the issue with the full tank and in descent, this alarm in the beginning of the dive should never pop-up.

I have also submitted them the logs and model / Serial numbers etc… but didn’t hear back from them yet. The alarm in my last dive at 6m was not scary… the one I got at 33 meter was !!! I simply hope that I never get an alarm in the beginning of a dive which is relevant because now treat them all as irrelevant.

hhouter

@MartinPadiPro I have two buddies who also have a Nautic. This issue was seen by both, but they don’t bother to submit to Suunto. So it is definitively not a standalone problem…

VoiGAS

@MartinPadiPro Sounds like a bot, all those answers don’t make sense for the described situation. I hope Suunto is taking that case serious, after algorithm lock and depth sensor failures it could be the next fiasco pushing customers to Garmin or Shearwater.
Thats a shame, when I started diving the question was just which Suunto to choose as a dive computer. Everyone had Cobras, Vypers and then Zoops, but it had to be a Suunto

hhouter

@VoiGAS On my first dives with the Nautic I was wearing my EON Core on my other arm to compare RGBM vs buhlman. So the first dives and my first Mandatory Gas’s Time Alarm were recorded with two Suunto dive computers on one POD. The Core was flawless and didn’t have any interruptions, but the Nautic gave the error. This is why I think there is a bug in the algorithm calculation of the Nautic.Due to the fact this was my first Mandator Gas Time Alarm, I ascended immediately after the alarm. Both logs were sent to Suunto support. See both logs, below:

VoiGAS

@hhouter little bit offtopic, but I am really interested in your experience with the two algorithms. Maybe you like to share them here: https://forum.suunto.com/topic/15559/bühlmann-vs.-rgbm/10

hhouter

@VoiGAS Yes, will respond with my findings there.

ccrhenrik

A question to make things clear. You only get this alarm on the Nautic, not the other air integrated computers? The problem is with the Tank POD not the older transmitter?

hhouter

@ccrhenrik Correct. Two computers connected to same Tank POD. The EON Core does not give me the error, the Nautic does. See screenshots of same dive in post above. The tank pressure graph in both computers are equal and do not indicate any loss of pressure, see screenprints below.

So my conclusion is that it is not a tank pod error or inteference of a flashlight as the EON didn’t give me the error and functioned correctly. There should be a bug in the Nautic as it indicates the 5 Minutes Mandatory gas time alarm with full tank in certain situations in the beginning of the dive.

See both logs;