Garmin UltraTrac Overview
Garmin UltraTrac is a battery saving mode on Garmin watches for hiking. The idea here is that a Garmin watch can capture your GPS position at longer intervals and save its battery life in order to allow you to record longer routes without recharging. What you gain in battery life you lose in detail of your recorded track.
Garmin Watch Info
For this UltraTrac Review I used the Garmin Fenix 5x Sapphire (Amazon Affiliate), which is not the latest Garmin Fenix Watch on the market at the time of writing.
The current generation of Garmin Fenix watches as of writing this review is the Garmin Fenix 6 (Amazon Affiliate).
Garmin describes UltraTrac on their website as:
An ultramarathon (ultra distance) or extra long hike may require a decrease in track detail to ensure sufficient battery life of the device, while a normal activity may benefit from greater detail. UltraTrac is a GPS mode that decreases the update rate of GPS data to once a minute, providing much longer battery life while in GPS mode.
I decided to test out the Garmin UltraTrac while on a local hike in San Diego at Daley Ranch, and I also used it while on a longer backpacking beach camping trip to Santa Rosa Island.
Garmin UltraTrac Review: Day Hike
The Daley Ranch hike was supposed to look like this:
While hiking I used Garmin UltraTrac and this is what the hike recording actually came out to be:
I obviously was not expecting the Garmin UltraTrac to be right on the money following the path the entire time. Since UltraTrac is only taking my GPS position every minute it is basically connecting each position with a straight line. I would expect straight paths to be fairly accurate and curvy paths or switchbacks to be a lot less accurate.
Before we dive into the details let's look at the distance should of been vs what was recorded:
- Actual Distance: 5.83 miles
- UltraTrac Distance: 11.12 miles
Garmin UltraTrac was 5.29 miles off in distance! That's a huge difference in mileage!
If we break this hike down into pieces we can analyze where the accuracy of the Garmin UltraTrac broke down.
Looking at the map data, the first part of the hike went really well for UltraTrac:
The trail at the start was fairly straight with no sharp turns, and I would expect Garmin UltraTrac to be fairly accurate here and it did an acceptable job here.
The first real accuracy problem for UltraTrac came up when the trail started to change direction 180 degrees:
Again polling a users location at a slower rate, I would expect it to struggle a little with a trail changing 180 degrees in direction but this was not a sudden sharp turn. I would have more expected it to just cut across the area between the two trails. As you can see in the image above it started to do this and than kind of just went all over the place once we got across to the other trail and change direction. It would seem that when we changed direction the GPS had trouble locating our exact location and maybe rushed and took an inaccurate reading and shut back off.
From Garmin's description I quoted earlier they just mentioned it changes the interval of polling a users location to one minute. From the data above it looks like it comes one every minute attempts get get an accurate reading and if it cant get a precise reading in a certain amount of time than it shuts off and takes a reading with what ever accuracy it had before time stopped. From a programming perspective I would maybe give it more time to get an accurate reading before just selecting the best available. I understand that it all depends which GPS satellites are within line of sight when GPS turns back on but I would take longer intervals between polling if they had to allow GPS to be on longer to record an accurate data point. Essentially I would recommend less but more accurate points if I had the choice.
After this change of direction UltraTrac seemed to get back on track until we stopped for some pictures by the lake.
I would think while stopped and not moving Garmin UltraTrac would be the most accurate but I was wrong. It was while stopped UltraTrac was the least accurate. I think my comment earlier about the GPS turning on and not getting an accurate fix before recording your location shines true when we observe what happens when stopped. It looks like Garmin UltraTrac will keep polling every minute while stopped and each inaccurate fix gets recorded and connected like a crazy game of connect the dots which keeps increasing your total distance...
This theory became very evident during our longest break, which was on top of Stanley Peak. We stopped to enjoy the view, take some pictures, drink some water and have a snack. It was the longest break and also our most inaccurate readings from Garmin UltraTrac.
Just to be clear we did not fall off Stanley Peak....
I knew going into this hike that UltraTrac was not going to be 100% accurate and I expected it to be cutting some corners off. I did not expect it to go nuts when we stopped for breaks. Overall UltraTrac added 5.29 miles to our entire trip! Next time I get out on the trail for a day hike I will try pausing my activity every time I take a break and this I suspect will make UltraTrac overall mileage data a bit more accurate.
Garmin UltraTrac Review: Backpacking Trip
I also recently went on a 54 mile backpacking trip on Santa Rosa Island off the coast of Southern California and decided to use UltraTrac while hiking across the island.
I used Garmin UltraTrac for all 4 days but for this review we will look at the longest hike of the trip.
Before we dive into the details lets look at the distance should of been vs what was recorded:
- Actual Distance: 14.65 miles
- UltraTrac Distance: 17.45 miles
For this trip it was only 2.8 miles difference. Why was the day hike with UltraTrac off by 5.2 miles and our longer backpacking hike was only 2.8 miles? One would expect a longer hike to have a greater variance in accuracy with UltraTrac.
Before we answer that question let's take a quick look and compare the map data.
Garmin UltraTrac Plot:
Since this was a longer hike lets zoom into the UltraTrac data and take a closer look:
That looks really good to be honest for only polling my location every minute. There are two spots that look pretty messy and those were probably longer breaks.
If we continue along the trail looking at the Garmin UltraTrac plot, it looks really good.
Based on the data I shared at the start of this section, it was expected that these map plots of the UltraTrac data would be a lot cleaner than the day hike UltraTrac data. So let's go back to why the backpacking trip long hike was more accurate than the day hike.
- This hike was 3 days into our trip, we had already hiked across the island once and had heavy packs on when compared to the day hike. Hauling heavier weight and having tired legs resulted in us hiking slower here than we did on the Daley Ranch day hike. Moving slower means we covered less distance during each 1 minute between the GPS taking our location.
- Since this was a longer hike, I paused my Garmin Fenix for most of our breaks because I didn't want to have to charge it mid hike. As observed when we looked at the day hike data, it was the breaks we took that affected the accuracy of UltraTrac the most.
Garmin UltraTrac Review Wrap Up
Garmin UltraTrac is a fantastic way to prolong battery life while out hiking on the trail, but you need to understand how it works to make the most of it. If you are moving quickly across the trail UltraTrac will be less accurate than if you are moving slowly weighed down by heavy packs. My last piece of advice is, if you plan on stopping while using UltraTrak make sure you pause your workout!
ℹ️ Gear Recommendations
If you would like expert gear recommendations for your next adventure check out the Ten Digit Grid Gear Locker. I detail why each item has a spot in my backpack!