I'm new to this site and this is my first posting so I do not know if this subject has been covered previously. I have a Garmin 1390T and wanted to get multiple maps to overlay each other.
I have a map of North America and a map of the US West Coast National Parks and wanted to be able to overlay them on an SD card. After much searching with no success I decided to join the two maps using the GMap tool and put the combined map on the SD card. Now when I start my Garmin I get my home country, North American and the US West Coast National Parks maps. The Garmin has recognised the two maps in the one file on the SD card as seperate maps and I can turn any of the maps on or off individually. I hope this is some use to fellow users.