When I say "true GPS" I mean the ability to function independently of a data service in conjunction with a mapping program like Google maps? Driving from Porto to Lisbon airport, I was running a bit late, and ran past the precise ending hour for my data package with the SIM chip in my Vodaphone hotspot. When the data plan expired, my iPad and iPhone 6 Plus went blind. I figured that if the iPhone 6 Plus had true GPS, it could pick up satellites without a data plan - and that a true GPS integrated with Google maps would have continued to show my position on the main highway, but it didn't - and it sure didn't on my iPad 3 running iOS 8 (at the time). It seemed that any GPS function on either device was still linked to a data plan. I now have an iPhone 7 Plus (bought unlocked for cash from my local Apple store, now with a Verizon SIM in it). I am leaving in 2 weeks for Greece and Norway - the case of Norway, I will be up in the thinly populated fjords north of Bergen, and in Greece, the less thinly populated regions of the Peloponnesus. I plan to purchase SIM chips for my iPhone 7 Plus and my hot spot because it's easier for my partner to navigate for me on my iPad Pro 9.7. My question: Do I really need SIM chips for navigation, or just for data/phone comms?