GPS guided turn-by-turn directions will work uninterrupted even if you hit data dead zones. But one snag I encountered was when I tried to program new destinations into the downloaded maps. Google kept trying to connect to the Internet to determine the best route. Even though I couldn't program Google Maps to give me turn-by-turn directions I could easily follow the Google Maps to where I wanted to go.
Google Your Tour Guide
A fantastic planning tool for vacations is the ability to build Custom Google Maps. These maps give you valuable context of where you are headed and what is nearby. You can easily use them to create itineraries based on what’s close and figure out the most efficient way to go from point A to B. After you've created and saved a custom map you can later call it up on your smartphone or tablet when you get to your destination.
With the new Google Maps interface it's not so easy to access the Custom Maps feature anymore. With the previous version of Google Maps there was a shortcut to My Places where you could create Custom Maps right from the main Maps page. With the new Google Maps, first open up Maps and look over in the upper-right-hand corner and click on the Setting icon (that's the one that looks like a little gear - see above image). A drop-down menu will appear with the option My Places. Click on that and now you'll see the tabs All, Maps, Starred, and More. Below that you'll see the option "Create Map."
One of the best features of Custom Maps is the ability to collaborate and share maps with others. This lets a group of people to create a shared itinerary - allowing multiple people to suggest points of interest to visit without one person hijacking a trip.
The holy grail for any out-of-towner is finding the great local haunts and avoiding the typical tourist traps. Of course there are great tools such as Yelp for finding great places to eat. But with Google's newest rev of Maps social now becomes front and center, putting reviews of restaurant and attractions directly on local maps.