Can an Apple Watch track a hike without your iPhone nearby?

The short answer

Whether a hike gets tracked without an iPhone in your pocket comes down to what is actually holding the GPS receiver, not whether a watch happens to be on your wrist. A watch with built-in GPS and a workout app designed to record on the watch itself can log a route with the phone left at home, because the watch is doing its own positioning and saving its own file. TrailCam is an iPhone app — the recording, the GPS reads, and the photos, clips and voice notes you pin to the route all happen on the phone. A paired watch does not change where that recording is taking place.

What actually has to be true for a watch to record alone

• The watch needs a GPS chip of its own. Not every Apple Watch model has one; some rely on a paired iPhone for location entirely, in which case leaving the phone behind leaves the watch with nothing to record position from either.
• The app doing the recording has to be built to run and save on the watch, not just to mirror a screen from the phone. A watch face showing a phone app's output is a display, not a second recorder.
• The watch still has to be the thing physically travelling the route. None of this is about the phone versus the watch as brands — it is about which device is actually carrying a working GPS receiver along the trail.

Why a phone-based app records on the phone, not the watch

TrailCam pairs with nothing and mirrors nothing — the GPS track, the elevation readings, and every photo, video clip or voice note you capture along the way are all handled by the iPhone directly. That is also why keeping the phone in a pocket or a pack rather than checking a watch does not cost anything: recording keeps running with the screen off or another app open, so there is no need to have the phone out and awake for the track to keep going.

This is a reasonable way to build a hiking app rather than a limitation to route around. Capturing a photo, a clip, or a spoken note pinned to the exact spot you are standing needs a camera, a real screen and a microphone doing real work, not a glance at a wrist — the phone was already the tool for that half of the job, so it makes sense for the GPS half to live there too.

What actually happens if the phone stays behind

If the iPhone stays in the car, at the trailhead, or at home, TrailCam has nothing to record from for the entire time it is away, regardless of what is on your wrist. A watch worn during that stretch is not quietly filling the gap on TrailCam's behalf unless it is running its own independent recording in its own app — and even then, that would produce a separate file on the watch's own app, not a route that shows up inside TrailCam. The two are not aware of each other.

Things that trip people up

• Assuming a paired watch automatically extends a phone app's GPS range — pairing shares notifications and some data between the two devices, it does not relocate where an app's own recording happens.
• Expecting a watch's own workout history to merge into a route recorded by a different app on the phone — they are separate recordings in separate apps unless one is deliberately exported into the other as a file.
• Leaving the phone in a bag "just in case" the watch covers it, when the app actually doing the recording only runs on the phone.

Where TrailCam fits in

TrailCam records on the iPhone itself, keeping the GPS track running in the background while the screen is off or another app is open, so there is no real cost to carrying the phone rather than trying to leave it behind. Photos, video clips and voice notes are captured on the phone too, each pinned to the point on the route where you took it, so the one device ends up holding the whole walk — the line on the map and everything you stopped to notice along it. TrailCam is free to download.