Most GPS running and multi-sport watches tell you when they have a lock to the GPS satellites overhead. Unfortunately, the Apple Watch doesn’t—at least not without using a third-party app like Runkeeper or Intervals Pro. But there are a couple of workarounds.
Most of the time, the GPS in your Apple Watch should work invisibly. Within a minute or two of starting an outdoor workout or other GPS-tracked activity, it will just have a good lock. And, if there are any gaps or short sections it loses signal for, it will use your pace history, stride length, the accelerometer, and other personalized information to estimate and fill things in.
However, while you can’t confirm your watch has a GPS lock mid-workout, you can check it’s using “Location Services.” These are, basically, GPS plus Assisted GPS (aGPS), cellular positioning, Wi-Fi network positioning, and any other way your watch can possibly find out where you are.
To check, swipe up on the main watch face to access the Control Center. If your watch is using Location Services, there will be a solid purple arrow in the top right corner. (If the purple arrow is just a hollow outline, it means that an app could possibly receive location data but isn’t currently doing so.)
Now, this just tells you that your watch is using Location Services. It doesn’t mean that it’s getting accurate location data (or any at all). Assuming all is well with your watch, it’ll get a GPS signal as soon as it can. If you’re indoors, under trees, or if there’s something else interfering with it, it might not have GPS at the current moment.
If you’re not sure your GPS is working and need to troubleshoot it—or just want to guarantee you’ve got a lock before an important timed event—there’s a way to force things: use the Maps app.
On your watch, open the Maps app. To find your location, it has to use Location Services (you can check in the Control Center, if you like.) Most importantly, it will display the results right in front of you.
The size of the location circle will give you an idea of how good a GPS signal you have (or if you have one at all). GPS is accurate to a couple of meters, so if the circle is larger than that, your watch hasn’t got a strong satellite fix yet. If you’re standing out in open terrain and still can’t get a lock, something’s probably up with your GPS and you should contact Apple support. (Or, I suppose, nuclear war is about to break out; in which case, there’s no need to contact Apple.)
Tip: Your watch also piggybacks off your iPhone’s GPS signal. If you’re trying to troubleshoot your Apple Watch’s GPS signal, turn off your phone and then open Maps on your Watch.