Crossing from Galapagos to Marquesas

I admit that for some it may have only historical interest, but for me, it is not only a hobby but a great and important asset for anyone venturing offshore. I am talking about celestial navigation.

I learned it alone, using a great book adopted by the Brazilian Naval Academy, and being an engineer and liking numbers and equations a great deal more than most other people, decided to deduce the relations starting from the spherical triangles geometry basics.

I decided that I should be able to do it even if I did not have the sight reduction tables on board, so I adopted a method that you can solve with a scientific calculator, and the result you can see on the appendix to Roberto Barros´s book Rio to Polynesia, which you can download for free from his site here.

We hope someone finds it helpful. We have a friend who was circumnavigating with his parents and doing homeschooling at the time ( he was 17 then ) who managed to work out a sun sight just by reading and following the material contained in the book.