Has anyone used to navigation feature on the 645? I understand it's Garmin's first Forerunner that accepts courses and displays them on the watch without a map underlay. How is your experience following pre-saved tracks on it? My main use is when abroad without knowing the area. Is there a sort of turn-by-turn feature?
I suppose underlay maps will never happen on this device, or would it be possible? I don't refer to dwmaps which need an active internet connection to be displayed.