I've been researching this and found this snippet. Preview mode is functional, but really is a pain to use compared to normal mode. There is no turn-bu-turn nav as is normally provided (at least in the States and also in Bali and Thailand when I visited last year).

However, even with downloaded, offline maps, all I can get is Preview mode. Google maps works in Morocco, both for walking and driving. I believe the number of maps you can download is limited purely by the space available on your phone. It occupies 17MB of space on the phone and expires in 29 days. For me the Marrakech download took less than 10 seconds. It asks whether you want to download the map you previously selected as the area. Then click on the 'hamburger' icon (three horizontal bars) at top left and choose 'offline maps', then 'custom maps'. With Google Maps on an iPhone (I imagine the procedure with Android is similar), get the area you want to save on the screen-for example the whole of Marrakech. You can't download Apple Maps, but you can store offline maps from Google Maps and. You can download offline maps for Morocco before leaving home, you can also use the free wifi (pronounced wee-fee) facilities at many cafes. With Google Maps it will also indicate the direction you are facing, so you know which way you are walking. When you need to know where you are, the phone's in-built GPS receiver (which doesn't need a data plan) will show your position on the offline map. without direction instructions) by downloading one or more offline maps. If you don't want to purchase a SIM data plan whilst in Morocco you can still use your smartphone maps to perform simple navigation (i.e.

Download maps & navigation