My sextant

I started an on line astronavigation course a few years ago but got just too busy to finish it. I suspect I would have forgotten most of it by now even if I had managed to complete it. I remember trying to plot our position at home once by taking a sight of the sun in a bucket of water. There was a clever bit of maths that I've forgotten which meant that you could do this. I was about a mile out in my position fixing which I was quite pleased with at the time ,but I suspect there were all sorts of errors which somehow cancelled one another out. Maybe I'll have another go at it one day . GPS is a lot easier and I'm sure is much more accurate