Angus
I find this navigating lark really quite interesting as I'm sure many others here do as well. Perhaps you would consider, when time permits, elaborating on it a bit more.
With my flying background, I think the principle is similar, but not the same (and in my single engine Firefly I've never had to navigate further than the next airfiled, so I've never plotted a long journey).
Of course I would never encourage a goderator to go O/T, so perhaps a new thread could be found for anyone who wishes to discuss navigation/ getting lost for ships?
"This is TomTom. At the next bouy turn starboard and continue to the pier, then take the second exit from the harbour...." BANG.