Like Uber Crack said, you can change your default navigation settings in the Uber app. I have mine set to Waze. On my phone (Android) this is how it works: After I hit accept/start trip, the Uber app will automatically show its own navigation to the riders location/destination. If I hit the navigation button it will open Waze in a new window and automatically enter the address shown in the Uber app into Waze. It should work the same if you set Google Maps as default. I don't know what the navigation button does if you set Uber nav as default.