For some unknown reason, the latest Google Map 7.0 had removed the cached offline map features from the previous version. In previous version, you can select an area of your map and save it for offline usage. This is exceptionally useful if you are oversea and do not have any mobile data connection when you are on the road.
For the latest Google Map 7.0, Google actually did not removed the feature, but, they make it more user-unfriendly to use the feature. There are 2 ways to cache offline map
Using "ok maps" command
To use "ok maps" command, follow the following steps
1. Search a location you want to go. For example, Boston, MA. You can zoom your map to your desired size before caching. It will cache the map based on the on-screen information
2. If you are happy with the zoom, type "ok maps" at the search bar and click on the search button
3. Then, Google Map will start pre-loading the map with a progress bar. When complete, it will prompt a message "The on-screen map area has been cached"
Cache offline map based on search location
In addition to "ok maps" command, Google actually allow you to click on a link to make the map available offline. Follow the following steps
1. Search your interested location. For example, I searched Boston Public Library
2. When the search completed and Google Map will bring you to your location. Now, click on the search icon.
3. It will bring you back to the search interface. Now, click on the X icon
4. Clicking on the X icon will make Google to provide suggestion based on your last search. Now, scroll down to the bottom of the Google Map recommendation page.
5. At the bottom of the page, you will see, a link "Make this map area available offline". Click on this to cache the map area for your search location