I haven't been able to find out decisively whether the etrex 10/20/30 proximity alert functionality doesn't already have this behaviour (I don't own one but may consider getting one) but I've asked here and it seems to be lacking the behaviour I'd like -
- The proximity alert feature to draw the associated alert centre point and zone/radius circle on the map view.
- If I were to get an etrex, I'd be using it when I wouldn't be able to hear it, so just a beep for a proximity alert would be no good. I'd want some kind of visual indication too.
- With a visual indication, I'd like it to also switch to a map view, from whatever screen it's currently on, to better show me where I am in relation to the zone.