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Pub. No. 229 is way too cumbersome to lug around so I solve for Hc and Zn using the respective formulae for them.

These are handy to carry- http://thenauticalalmanac.com/Formulas.html

and a lot lighter than books.

Messing around with the various formulae to determine Z led me to the one on the Formulas page.  Most of the others require too many conditions ("if, then") to arrive at a solution.

Would like to hear what others use or maybe a quicker method.

Fb

(12-16-2015, 05:34 PM)Fred_B Wrote: [ -> ]Pub. No. 229 is way too cumbersome to lug around so I solve for Hc and Zn using the respective formulae for them.

These are handy to carry- http://thenauticalalmanac.com/Formulas.html

and a lot lighter than books.

Messing around with the various formulae to determine Z led me to the one on the Formulas page.  Most of the others require too many conditions ("if, then") to arrive at a solution.

Would like to hear what others use or maybe a quicker method.

Fb

Fred,

Here's the one I use (you mentioned earlier);

Cos-1((Sin(Declination) – Sin(AP Latitude) x Sin(Hc)) / (Cos(AP Latitude) x Cos(Hc)

Pretty easy to enter except you must calculate Hc using this formula first;

Sin-1(Sin(Latitude) x Sin(Declination) + Cos(Latitude) x Cos(Declination) x Cos(LHA)

Much easier than hoisting Pub. No. 229. 

How fast are you at getting both answers?

Roland D.

How fast in getting Hc and Z?

Probably about 1 minute if being cautious and pressing the right buttons.

The calculator makes for an easy entry. Casio, perfect for what these purposes.