Its possible to save yourself some cash when purchasing a Garmin Edge 800 without any Garmin maps or from needing to upgrade any delivered Garmin maps as maps from the Openstreetmap.org project can be used quite easily on the Garmin, here’s how. The maps are routable in most cases, can have contours or even versions that look like OS maps.

1. Go to the Openstreetmap Wiki and click on a map provider for your country / area of interest. As I’m in the UK I use maps from the Several European Countries section, specifically from Talkytoaster.
2. You have to enable data recording on the SD card by changing the settings: Settings > Data Recording > Record to memory card.
3. Place a blank SD card in your Garmin, turn it on and then start the timer. This will create the proper directories on the SD card automatically. Or use the SD card your Garmin was delivered with, just don’t delete the original map files (*.img files)
4. Plug your Garmin into your computer. Depending on your computer, you will probably be prompted to open a folder to view the files on both the main unit and the SD card. Otherwise, navigate to the drive/folder your computer assigned to your SD card.
5. After downloading the IMG file from the map provider, copy the IMG file to the SD cards “GARMIN” folder that was created earlier.
6. The SD card can have multiple IMG files on it and you can choose between them in the Edge 800 configuration menu.
7. Once the file is copied, safely remove (right click on the icon in the lower right of screen for Windows users) the SD card from your computer.
8. Insert the card and power up the Garmin.
9. Go to the configuration menu, then System -> Map -> Map Information, and select the map type.
10. Simples!