GPS accuracy on Trail running and Max GPS.

I used the watch on this setting for a 100 mile ultra on Friday and the distance was wildly over what it should have been At 33 miles the watch had recorded 43 miles! Is there a reason for this? What is the best setting for very long runs? This was the reason I bought the watch long battery and not too bulky. Thanks, Bill

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wcrowther over 3 years ago in reply to kidney_thief +1

Thanks for the answer, I'm going to look into disabling everything but GPS and carry a battery. This ultra was a test run for my main event in August - UTMB so good to sort out these issues now. Bill…

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0 kidney_thief over 3 years ago

The Max Battery power profile enables UltraTrac. UltraTrac is waking up the gps very rarely (not sure exactly, but like once per a couple of minutes) and the accuracy is a complete mess. If I were you (I'd love to run ultra one day) - I'd charge the watch prior to the run and it should last ~40 hours (EDIT: with solar, otherwise it might be hard). If you plan some brief sleeping sessions during the run you can pause the activity and use 'Resume later' which will bring you back to watchface, but pressing gps button will immediately go back to paused activity.

0 kidney_thief over 3 years ago in reply to kidney_thief

here is a thread about why UltraTrac miscalculates the distance. Sadly I don't know any way to fix this and afaik it's a problem with every Garmin that uses UltraTrac, not only Instinct 1 or 2.

One proposed solution is to export the activity and import it again and Garmin Connect backend will calculate the distance correctly then.

0 wcrowther over 3 years ago in reply to kidney_thief

Thanks for the answer, I'm going to look into disabling everything but GPS and carry a battery. This ultra was a test run for my main event in August - UTMB so good to sort out these issues now. Bill

0 kidney_thief over 3 years ago in reply to wcrowther

Good luck with UTMB, that is some legendary stuff!

0 wcrowther over 3 years ago in reply to kidney_thief

Thanks, it's an absolute bucket list race for me

0 3028432 over 2 years ago in reply to kidney_thief

How do you do this? My elevation wasn't correct yesterday. Climbed up and down ravines on a trail run and it said it was flat...

0 trux over 2 years ago in reply to 3028432

3028432 said:
My elevation wasn't correct yesterday. Climbed up and down ravines on a trail run and it said it was flat...

It looks your altimeter does not work. Could be due to some dirt in the sensor port, hardware failure, or it could be disabled in the settings (set to the mode "barometer only"). Open the ABC widget, note both the air pressure and the altitude, then climb a floor or two, and see whether one of the values changed. If only the air pressure changes, check the settings, and change the mode to "auto" or "altimeter only", and test again. If one of the values changes, look with a magnifying glass into the sensor port (or make a macro photo of it), and see whether there are some debris or dirt.

On the activity page in Garmin Connect Web, you can enable the Elevation Corrections, to see the elevation profile of your run, even if there is no data from the altimeter: What Is the Elevation Corrections Feature in Garmin Connect? | Garmin Customer Support

0 3028432 over 2 years ago in reply to trux

Thanks so much! It wasn't set to auto in the settings.