This is more a memo to self than a blog post. For an up to date map for the Garmin eTrex 30 go to Garmin Openstreetmap and download the required map. Then copy the file on to the SD card into a top level folder called Garmin, my Great Britain map has the filename gmapsupp_GB.img for instance. And that’s it, the map can now be enabled from the appropriate map menu. Routing works, but takes interesting turns for longer distances.
Similarly, tracks go into the Garmin/gpx. The can be selected as routes from the menu. The file Barry_s_Bristol_Ball_Buster.gpx gets displayed as Barry's Bristol Ball Bust for selection.