NavList:

John,

Thanks for your reply.

I have 2 books on Celestial Navigation, Mary Blewitt and Tom Cunliffe. Fortunately they both use the same methods. Determine GHA/LHA and declination from the nautical almanac then enter AP3270 vol 1 2 or 3 and find your Z and intercept or Zn and intercept. So yes am using intercept method. Do not know of another and for the time being feel it is wise to learn 1 method at a time.

I note using AP3270 vol 1 when you plot your LOP's and decide on your fix your work is not yet done. There is the matter of precession and nutation in table 5.

I am not familiar with calculators, do not have one but found one online and tried the COS 53 and the answer is -0.918282. You get 0.6018

What have I done wrong?

Thanks

Mike