Solved the Mapping Problem

Following on from my previous blog I'm now thrilled to say that I've solved the problem! For the benefit of those who care, here's what I did.
I checked I had Google Earth installed.
Then I downloaded the excellent UK Canal Routes map from coobeastie.co.uk
I chose the downloaded kmz file to open in Google Earth.
Knowing I wanted mainly railway lines and stations I selected More > Transportation > Rail in the Layers panel and unticked mostly everything else.

River Ouse and Railway Bridge at Ely

Finally in the Places panel I ticked My Places > Temporary Places > UK_Canals_Route_only and ticked absolutely everything within that. If you're only interested in a small number of canals you need only tick those you need. Screenshot below with Ely station highlighted for clarity.

So here's my next (or the one after that...) project - noting railway lines near to canals so I can moor up, catch a train and come back later - or friends and family can catch up with me while I'm away.
Next, to find friendly folks who will accept me mooring for a short while and where I won't block anyone else - a bigger problem altogether!