How does the GPS work?

The GPS is enabled when you select an activity from the Sports widget. The watch will automatically initiate the search for a GPS signal.Wait until GPS has full signal and tap “GO” to start an activity.

The GPS route is recorded and will be displayed on the watch and mobile application.

There isn't an actual setting to turn off the GPS mode as it should automatically disable once you have stopped or completed your activity from the Sports widget area of the watch.