There was a learned lecture tonight in the local chapter of the RIN, about the next satellite navigation constellation, Galileo. It will, apparently, do wondrous things - including making a lot of money for some entrepreneurs - but one thing it won't do is help check the magnetic compass for error. And, as every schoolboy knows, going out of sight of land for a while requires one to check the main steering compass regularly, so one can be more confident of finding said land again.
So I found myself looking up Sun's Amplitudes again - especially as I'd just given away my copy of 'Selected Star Amplitudes' to another geek, who has unearthed a WWII sun compass from his attic.
Now, I don't propose an outbreak of compass calibration - that would break the habits of a lifetime for many - but knowing what's involved, and where it's to be found if wanted, seems to me to be appropriate 'Just In Time' seamanship. Even Christopher Columbus did this sometimes, when stuck for a better idea. Anyway, here are a few starter sources.......
http://www.qarlos.free.fr/navegacion/Se ... sson19.ppt
http://www.irbs.com/bowditch/pdf/chapt17.pdf
http://www.tpub.com/content/administrat ... 20_268.htm
