If you’re only visiting the major cities and key attractions, such as Etosha National Park or Sossusvlei, then you almost don’t need any navigation tools at all. The main roads are well signposted and tend to make a direct line between points A and B. As soon as you head off road, however, it’s vital to have a GPS and map book, and if you’re driving through Kaokoland then a satellite phone is also a good idea. 
4G mobile cover is limited to the major cities, and there’s only intermittent 3G around the smaller towns and along national highways. Otherwise there’s only scattered and often frustratingly slow 2G, and there’s no coverage at all along the Fish River Canyon, around the Namib, throughout Kaokoland, and on The Skeleton Coast. The MTC network has the best coverage. Save on roaming fees and buy a local SIM card when you arrive.
