There we are, I've spent my leaving present from N.W. Hertfordshire Hospitals NHS Trust and have bought a state of the art G.P.S. system for footpath walking and geocaching.
It's a Satmap Active 10 - and it's pretty amazing, so far...
The system uses Ordnance Survey maps on SD memory cards and I have bought a 'custom built' map covering the area I think I will need locally. When I planned it out on a paper map it turned out to be 80km x 50km and happened to be centred on Luton Airport.
O.K. the map alone was over £100, but look at what it does...
Initial screen before unit obtains 'home co-ordinates'
Zoomed in on Redbourn
One of the roads around the common.
It is possible to zoom in even further but obviously a lot of detail is lost. At this level you can easily see which side of the road you are walking on.
The beauty of this unit is that you need no longer worry about straying from a footpath and walking through a farmyard which is 'out of bounds'. As soon as you stray from the footpath, it's immediately obvious on the screen. Just to left of the road below, you can see a footpath across the common clearly marked in green.