Thanks. I think I'm on default settings, but what I have in this is:
Auto Zoom: On
Zoom Levels Points, Streets etc: all four set to Auto
Should it be relevant, I'm using OSM UK maps (downloaded from the links in this thread.
I've just discovered my Etrex 20 has an auto-zoom function, but as far as I can tell it doesn't do anything! What would be convenient would be for the map to zoom in as I approach a cache (or waypoint) - I tend to have it mounted on my bike handlebars, and it's too fiddly to adjust while I'm cycling. Any ideas whether this is possible? Thanks.
Cambridge Meridian (GC2WYEW) is right on the Greenwich Meridian, and there's a virtual at exactly 52 N 0 E. There's a few more near here placed on meridian stones, but since those follow the UK grid, they appear as about W 0 0.097 on here.