After an early VC10K trip to Akrotiri, we were enjoying a delicate little glass or few of brandy sour in the bar, as you do, when the nav instructor saw that it was a clear and starlight night. So he collared the student nav and off they went to the jet to do that weird astrology thing with a sextant and various mysterious almanacs and complicated forms.....
Which would probably have been OK, had they not enjoyed quite so much brandy sour beforehand. After much peering through the sextant and mysterious scribbling, student nav proudly came up with the lat/long of their location.
500 miles due east of Moscow! At which they repaired back to the pub and sorted out the errors on a couple of bar chits before we decided it was time for a kebab run.... "Chris - taxy for 10 to the Swan please!" "No sir, you go my place and I give you free kokinelli". Top chap!!