Originally Posted by
gauvins
Unless things have changed recently, gmaps is unreliable for offline navigation. It requires connectivity to compute a route, and if you deviate from a route set while you were connected, you'll loose navigation.
There are several great offline navigation apps. I use Locus pro / Android.
You can, in theory, download and cache Google map segments on the phone. So no data required as along as you are riding in the area the cached map covers. Never done it, I just use a Garmin.