You can get your free maps from
here ...
Select:
Generic routable
none
'leave it alone'
Enable manual tile selection ... tick it ...
Select the tiles that you need. To unselect just left click it again ... Only select the tiles you need as otherwise the file will be too large.
UK + Ireland + France + Belgium + Netherlands + Switzerland = 2.4GB thereabouts
I think if you live outside Western Europe, please check details on the maps on basecamp before proceeding ...
Enter your email address ... then click 'Build my Map'
You will receive a link in your email to download 3 files. 1 file (gmapsupp.img) for your SD card for the GPS. Another for your basecamp program and one more for apple users I think.
In your SD Card create 2 folders: EULA & Garmin
In the Garmin folder create 4 folders: Activities, Courses, NewFiles & Workouts
The gmapsupp.img file is saved in the Garmin folder. You might be able to get away with just creating a Garmin folder and saving the .img file in there. I have not tried that.