It's all going over my Head
20 March 2013
The sun is directly overhead now in the middle of the day - not precisely but as near as makes no difference. This presents a navigational problem. In an instant, the bearing of the sun switches from east to west as it passes overhead. I have been emkplying the tried and tested method of astro navigation and taking a morning sun sight, noting the log (Walker log off the stern rail) and the course, then taking a sight mid afternoon and bringing the morning sight forward to give me a afternoon fix. Some have turned out quite good- 5 miles my nearest and 130 miles my worst. But with the sun passing directly overhead, the morning and afternoon position lines are directly opposite each other in terms of the compass rose. For the best fix they need to cross at right angles, but now they are almost parallel. This can be fixed by employing the sun and, say, a planet. Jupiter is good for this at the moment and I have used her once or twice. But with these trade winds have come cloud so getting sights is not quite so certain as it was. I'll be glad when things are back in order; the latitudes are north, the sun is in the south at midday, and Orion is the right way up!