I did a quick rule of thumb; found a straight edge, drew a quick line, measured up a rough bearing.. .. .In my case, once on course, I was uncertain of position for quite awhile, but decided that - in the absence of any currency on Radio Nav - I would stick to my planned heading. Going off for a look-see seemed like it would really confuse things.. .. .Examiner afterwards said I'd done the right thing (he sensed I was 'lost'). I got my target right on the nose.