Garmin provide many types of maps for their devices but each costs quite a large sum of money. Thankfully in recent months this process has become a lot easier for the end user to do. This short guide will explain where to find the correct map file and how to install it using a Dakota 10 GPSr, a Mac and Garmin"s free software.
The OpenStreetMap project provides map data for a large amount of the world for free. Even though the project is community edited – its still an excellent free map to use on your portable GPSr device. If you take a look at the list of maps available on the OSM site (located here for the UK) you will see how many different people are providing packages/data files that can be used with Garmin devices.
The choice I made for UK maps with contours and routing is the maps created by user "Talkytoaster" and can be found at his website. At the present time the latest file is "101105" and the filename is "101105-UK+Contours-Routable.gmapi.zip" which will be a file compatible with Garmin"s MapInstall software on the Mac.
Once you have got your file downloaded (which is probably a few hundred MB) then unzip the file you downloaded. You can plug in your GPSr and run the Garmin MapInstall software on your Mac. Follow the process on-screen and after a short time it’ll be done. Reboot your GPSr and you’ll notice that while its loading at boot time you’ll have a piece of text that says "OPENSTREETMAP".