The downloaded maps can be installed using ManageMaps (a custom app from Garmin, not on the app store) or simply by copying the content of the zip to either:
- /Users/YOUR_USERNAME/Library/Application Support/Garmin/Maps/
- /Library/Application Support/Garmin/Maps/ (
See this for more info
While this makes the map available in BaseCamp it doesn’t really make it easy to download multiple maps and manage these. So download JaVaWa GMTK which is a utility tool to enable e.g. rename of the map making it easier to manage a set of different maps.