Hi Guys,
Just to be specific, with iOS 8.3 and above, the GPS works in Airplane Mode, so I think Chris's suggestion would work
Jonathan asked if he could turn off his phone, and use a Bad Elf device to update a track in Gaia by turning on his phone at a later time:
While Gaia is able to work with a bluetooth receiver such as a Bad Elf, it can only receive GPS points from a bluetooth GPS while the app is running, so you will have to leave your phone on to accurately record your track.
Regards,
Ashli Baldwin
Adventure Support