Thanks for all of the replies!
I was wrestling with it this morning and I can now remember what the last step was. Foxmoth was correct.
7. Rotate the wheel so that the TRUE heading lies underneath the top of the white wheel (INDEX)
8. Rotate the disc so that the amount of drift (i.e. the horizontal distance of the end point of the wind) matches the amount of drift at the TOP of the white circle (the true heading is underneath the part labelled drift). When those 2 matches (i.e. 20 or 30 or whatever it is) you then read off the heading from underneath INDEX.
Rather than try any new approaches I managed to get to the one I was shown and it's all ops normal again.
I was trying to read the Jeremy Pratt book last night but it may of well as been written in Chinese!
Thanks again
Last edited by PompeyPaul; 6th March 2007 at 12:51.