Garmin Venu 3 for Alps Hiking: How Accurate Is the GPS?
The Hike
Below is a hike (one of several) I planned for this summer.
As you can see, it is a 12.2 km hike with 730 meters of elevation gain:
Then I actually did the hike. I followed the route as planned, with no noticeable deviations from the plan, and tracked it with my Garmin Venu 3. I know the Venu 3 isn’t part of Garmin’s dedicated outdoor line (where the Fenix, Enduro, and Instinct sit), but it does support hiking. In fact, that feature was one of the main reasons I chose this model.
Let’s look at what the Venu 3 recorded for me:
So, 15.07 km distance and 815 meters of elevation gain. Not exactly what Komoot has planned for me. The elevation difference can be explained by Garmin using its barometric sensor (which is debatable for hiking), but the distance should be close to the plan, right?
A 3 km discrepancy on a 12 km track is a 25% error. That is huge. But why did it happen?
Here is some of the “why.”
GPS Accuray of Venu 3
As I said, I followed the trail (the dotted line), but my watch tracked something else entirely.
Below is my route there and back – taking the same narrow trail (the dotted line). Technically, there is no physical way not to follow it. My watch, however, had a different view:
GPS “Hallucination”
And then, this:
This is the Casinei Hut – a great place to take a rest and enjoy some local food. I spent some time there on the terrace (outdoors, but under a roof).
The same story happened here: everything inside the blue rectangle is a “hallucination” by my watch, to borrow a term from the AI field. I was sitting nearby and only went inside the building for about two minutes (the Maria e Alberto ai Brentei Refuge, in case you were wondering).
You might ask me: Why didn’t you pause your activity while you were resting in or near these buildings?
That is an excellent question; thank you for asking! The answer: the Venu 3 automatically ends and saves a paused activity after about 5 minutes – no questions asked, no option to delay. Other Garmin models allow you to pause an activity indefinitely (or at least for a really long time) and resume later, but the Venu 3 doesn’t. For hiking, this makes zero sense, but that’s where we are.
Ideally, the watch should detect that I’ve stopped walking and ignore GPS drift during that time. Alternatively, a proper manual pause/resume feature would do the trick.
I believe these two issues combined – very inaccurate GPS tracking on narrow trails and phantom distance accrued while paused under a roof – are responsible for those extra 3 km.
Other Garmin models might perform better, but a sport watch carrying a €500 price tag in 2024 should do better than this.
PS: By the way, the hike was great – I highly recommend it.
