Exactly Rob; My plotter seemed to be doing its job very well, it was ME that was not doing MY job so well.
When I looked back at my trail, it was like lots of quite tight S bends!!!
I could not beleive how disorientating the fog along with such a slow speed could be. The fact that we "should" be passing Aunt Bessie by now but were actually still in the lee of Rockley didnt help at all.