Open water GPS drifting

[Ze Stuart]

I have seen the same: I assume it’s due to the new GNSS firmware that was included with the update. Not enough testing!

[gerasimos]

@Artus-Diver before 2.42.12 GPS it was clean and smooth of the 90% of openwater activities

!

[CroShark]

Unfortunately I have the same problem with my Vertical Steel Solar.
The GNSS is great in land activities, but in Open Water Swimming is criminally bad.

In my last swim I achieved a top speed of over 90 km/h.
Before the swim I have followed all the necessary steps for a good GNSS signal (update with Android App, and waited 5 minutes on land before starting the swim).

The old Ambit 3 Peak was perfect for swimming.
I’m really disappointed with the Vertical in this segment, currently it is practically unusable for any swimming metrics.

[gerasimos]

@CroShark
Before the latest update, I had excellent results with the Vertical in open water.
I can honestly say that, compared to people using Garmin (fenix, forerunner ) and COROS (apex pro)devices (swim side by side always freestyle technique), my trackings were equally good — if not better and more reliable — even under cloudy skies and sea wave conditions.

I assume this is some kind of glitch or bug introduced in the recent update, as a soft reset hasn’t resolved the issue. I’m confident it’s not a hardware problem, since the watch performs flawlessly in every other use case.

I hope this will be improved in a future update, before I consider doing a hard reset.

[gerasimos]

@CroShark
I also did a test using a “ghost” open water swimming activity. When the watch detects that you’re moving too fast for typical swimming speeds, it displays a pop-up message saying that you’re moving at a speed that’s too fast for swimming and pauses the activity, asking if you want to continue.

This could be helpful in cases where the GPS reflects incorrectly and shows you’re moving at 90 km/h, so it notifies you with a message.
But didn’t work in my case into the sea

• ideally, such issues shouldn’t occur in the first place…

However, I want to try placing the watch inside a swim buoy, though it’s not as convenient as being able to quickly glance at your wrist.

[CroShark]

@gerasimos
Thanks for the suggestions.
During the swim I did get the message to pause my activity, because the watch detected a to high speed for swimming, but I ignored it.
This was the first time I received it during any activity.

I sparingly use the swim buoy, but placing the watch on it defeats the purpose of GNSS watch, like you stated.

I hope Suunto will solve this in the near future, I usually swim the most during August.

[gerasimos]

Fifth test in open water activity

1. I changed the watch to the other wrist (from left to right) in case symmetry during freestyle swimming was the issue.

2. I followed buoys in the sea that were in a straight line (500meter in one way).

3. GPS signal strength was between 75–85%.

4. Weather conditions were excellent – clear sky.

5. Brief stops with the hand completely out of the water for about 1 minute, to allow the signal to stabilize.

6. Never pressed paused

7. Before starting the activity, I waited 5 minutes after the GPS indicator turned green, for better locking, and of course synchronized with the app.

— Unfortunately, still very poor results (after last upgrade), even after a soft reset / profile deletion and creation of a new one same results and with default openwater profile.

Next step: Hard reset and test again…

[gerasimos]

@CroShark

Looking at the logbook history, I see much better recordings with the Suunto 9 in the same places several years ago, when supposedly GPS technology wasn’t as advanced as it is today…
Let’s see after my hard reset


[Ze Stuart]

Same experience for me, the track is basically a drunken squiggle. Nothing to be done but wait for a fix.

@isazi do you know if this has been reported?

[gerasimos]

@Artus-Diver this such a small deviation in the GPS is (in my opinion) absololutely nomral in a sea or lake enviroment

[Artus Diver]

@gerasimos
Of course, as I mentioned, I don’t have a major problem, but comparing my previous tracks from before the update, they look much better.

I think Suunto should investigate this.

[Ars Vitae]

I agree, same for me, since December 2024 GPS goes crazy as hell. Previously, I had not noted any problem. Let’s hope Suunto is aware of this and is working on a fix. I have let go the accuracy of this watch in the pool, but if this negative trend continues for open water swimming it will mean that the brand is moving away from supporting disciplines such as triathlon and swimming marathons.

[Ars Vitae]

To give an example:

[Ze Stuart]

I have one better. I started and finished within a few meters of each other, and swam in relatively straight lines up and down the beach, going down ~100m, back and so on. I know the distance because of the grounds on the beach, and can measure it using satellite maps…

If anyone wants to say ‘GNSS soak!’ I cycled for about 30m to the beach, and let the watch ‘soak’ for about 5m while getting ready. It had copied the bike ride to the watch before I swap, so it will have had opportunity to update the A-GPS.

This was with a Race, not a Vertical.

Then this was with a Vertical. Better… but for an out-and-back swim in calm water, not great.