Back in the early 90's a chum and I took a yacht from Mallaig to Oban via Barra on the west coast of Scotland. Hebridean Sea was, unnaturally, as calm as a mill-pond and we had to use the iron-jib. Halfway across I noticed that the sun and moon were at right angles to each other and so the Skipper and I got the hand-held sextant out, took a couple of sightings for a sun/moon fix, bunged the results into his TI hand-held calculator, as well as the tables, and came up with a fix that put us 500 yards off track! Not bad, we thought, considering the source was 92 million miles away . . . . . . .
