GPS Accuracy Test: Apple Watch Ultra vs Garmin Epix in New York City

Introduction

Multi-band GPS is the highest accuracy tier available in sports watches right now, and two flagship lineups carry it: the Apple Watch Ultra and the Garmin Epix series. To see how well that hardware translates into real-world track quality, we ran a demanding city test through New York, pitting the Apple Watch Ultra, Garmin Epix, Apple Watch Series 8, and Garmin Forerunner 955 against each other on the same run. The route deliberately includes the hardest GPS scenarios a city can offer: riverside paths with partial cover, highway underpasses, deep street canyons, small park trails, and finally Times Square.

The Route: Across Manhattan End to End

The run started at the very tip of Manhattan near the Staten Island Ferry, with a planned route of roughly 100 blocks along the outer edge of the island, cutting through Central Park, and finishing in Times Square. Running straight through the middle of the city would mean constant stop-and-go at every block, so the outer path made a better continuous test.

The riverside sections are a good first challenge: open sky overhead but running underneath the edge of overhanging structures. All four watches tracked remarkably close to the actual path here, with only slight differences between the Apple watches on the left wrist and the Garmin watches on the right. No massive errors appeared, and all tracks sat within a lane or so of where the run actually went. The sides were swapped mid-run to keep things fair for the sections that followed.

Under the Expressway

After crossing toward the Brooklyn Bridge, the route dipped below a highway overpass. This is where the tracks began to disagree. Under the expressway, all four watches drifted in different directions: the Apple watches pulled one way, the Garmin watches the other, and the Apple Watch Series 8 split the difference, seemingly getting it right more by luck than anything.

Back in the open, everything snapped back to normal and all units looked excellent, which is exactly what you would expect in wide-open sky. Once back under the expressway again, with sides swapped, the tracks slightly disagreed but none were horrible, and the Garmin Forerunner 955 was arguably the closest of the bunch. Overall it was roughly a wash.

Into the Big Buildings

Leaving the river behind, the route turned into the dense downtown core, with massive buildings on both sides. This is traditionally where wrist GPS falls apart. Here, most of the watches stayed on the road, occasionally drifting to one side or the other. The Apple Watch Ultra and the Epix largely held their own, aside from one block where every unit went a little wonky before consolidating again.

The wiggly sections through the shopping crowds still stayed largely on the road. Every watch took an occasional dip into the buildings, but only just past the front door rather than blocks away, which is a massive improvement over past years.

Central Park Recovery

Central Park served two purposes: seeing whether the watches recovered from the dense city sections, and testing how they handled small trails. At a high level, everything sat on the path, and zooming in confirmed every track was within essentially one runner’s lane of the actual line. That is very solid across all four units. A second patch of rain rolled in along the way, but it had no visible effect on tracking quality.

The Times Square Finale

The final stretch ran past super-tall buildings straight into Times Square, one of the most GPS-hostile spots in New York City and a fixture of this accuracy test for close to a decade. The results here were the roughest of the day. Things started well for the first block or two, then the Apple Watch Ultra drifted deep inside the buildings, half a long block off the route, before popping back. Units dropped in and out, with two or three of the four tracking at any given moment, and the Ultra repeatedly slipping back toward the buildings. It eventually looped around and landed near the center of Times Square where the run finished. It was not pretty, but every watch here was clearly improved over the same test in years past.

Which Watch Should You Buy

All four watches delivered genuinely strong tracks for the overwhelming majority of the route, and multi-band GPS on the Ultra and Epix did hold up well across riverside paths, underpasses, and downtown canyons. If you run mainly in cities with tall buildings, expect occasional drift in the worst spots regardless of which flagship you pick, and choose based on the ecosystem you prefer. The Forerunner 955 held up particularly well under the expressway, while the Ultra and Epix mostly stood their ground through the densest streets. The Series 8 tracked closer to its multi-band siblings than you might expect for a non-multi-band unit, though it drifted along with the pack in the hardest sections.

Conclusion

Across roughly an hour of running through some of the most GPS-challenging terrain a city can offer, the Apple Watch Ultra, Garmin Epix, Apple Watch Series 8, and Garmin Forerunner 955 all stayed impressively close to the actual route, with errors only in the harshest spots like deep underpasses and Times Square. GPS accuracy at the wrist has improved dramatically over the past decade, and any of these four is a dependable choice for urban running.