Just bought my Dakota 20, GPS functions: found myself on the right spot!
But, the world-map is not very precise though.
My first bubble: I generated the .zip map, to be used for the GPS, thanks to Lambertus,
but what do I do: put, copy, transport the unzipped file into the GPS or the zipped file, from which I cannot change its name. Thus I hope to copy the unzipped map, otherwise it is troublesome how to find the right map in the Dakota.
“gmapsupp.img” is the file to use. You can rename it, but the extension “.img” must not be changed (note that some older devices require the complete name “gmapsupp.img” - so try that first).
When the device is connected to a computer and visible as a mass storage device, you’ll find there a folder “Garmin”. Just copy the file into that folder.
Better: if your device can use an extra memory card, create a folder “Garmin” on it, and copy the file into that folder on the card: in case of a “broken” map, you can simply remove the memory card, while removing a broken map from the internal memory may be complicated…