The Apple Watch Ultra always uses its own GPS instead of your iPhone

If you’re thinking of buying a new Apple Watch, there’s something you should know about the GPS tracking. Apple has confirmed that the Apple Watch Series 8, second-gen SE, and Ultra won’t piggyback off your iPhone’s GPS signal if your phone is nearby. Instead, all three will rely on their built-in GPS sensors. Older models, however, will still use your iPhone’s GPS when possible.

While this change wasn’t a secret, it flew under the radar because of flashier updates like Crash Detection, temperature sensors, and, well, the Ultra’s entire existence. However, DC Rainmaker — a well-respected sports and endurance tech reviewer — spotted that Apple made it official by adding a line to an Apple Watch support page.

* Apple Watch Ultra, Series 8, and SE (2nd generation) use the built-in Apple Watch GPS even when your iPhone is nearby. To preserve battery life, older Apple Watch models use the GPS from your iPhone when available.

Older Apple Watches use your iPhone’s GPS when available as a means to prolong battery life. It makes sense. Continuous GPS tracking can significantly zap your battery, and the Apple Watch isn’t as useful as a fitness tracker and smartwatch if it can’t make it through the day. If you’re already carrying your phone along on an activity, why not offload a more power-intensive feature to the larger iPhone battery?

The problem is that, by prioritizing your Apple Watch’s battery life, you make tradeoffs with GPS accuracy. Unless your phone is always in your hand with nothing obscuring its GPS antenna’s view of the sky, your watch’s GPS is probably a more convenient and accurate option. As DC Rainmaker points out, if your phone is in your backpack or buried deep in a pocket or bag, relying on its GPS signal may compromise accuracy. It’s especially true for Ultra owners. The Ultra has multiband GPS, which means it can access both the L1 and L5 satellite frequencies for more accurate GPS data in challenging environments like urban cities and dense forests. If Apple had stuck with the old method, pairing the Ultra with anything other than the iPhone 14 Pro models (which also have multiband GPS) might mean you’d inadvertently end up using less accurate GPS tech. This ensures Ultra owners will always get multiband GPS.

But the big takeaway is that Apple seems much more confident about battery life on its latest Apple Watches — both as standalone devices and when used with your phone. For standalone activity tracking on cellular models, nothing’s really changed here. Meanwhile, if you do carry your phone with you, outdoor workouts won’t drain your phone’s battery as much anymore. That’s a win from a safety perspective, as GPS-only Apple Watches still rely on your phone to make emergency calls. You can exercise outside longer without having to keep as close an eye on your phone battery. As for the watch’s battery, Apple also added a new low power mode to watchOS 9 that prolongs battery life without sacrificing GPS or heart rate data.

Granted, this is most exciting if you primarily use your Apple Watch for fitness. Even so, it’s another small step toward erasing the line between smartwatches and fitness trackers entirely. Right now, battery life is a big reason why that delineation still exists. Fitness trackers can last a long time but often lack smarts, while smartwatches can do it all so long as you dedicate about 2 percent of your brain power to maintaining a charging schedule. Not having to make a tradeoff between features and battery life? That’d be a plus for everyone — not just athletes.