NavList:

Hello:

Thanks to a recent post by Greg which got me interested, I've learned to use Weems 1927 LOP book/method. I highly recommend it. It is one of the early short table methods, and it is quite easy. I was lucky to find a 1942/1943 printing of this very thin book (actually mostly Tables A and B) for solving the navigation triangle. The 1928 and later printings cover all latitudes. Only a nautical almanac is needed with the LOP Book .

H.O. 249 became available in the late? 1940s, and this latter method is more intuitive, but the results are exactly the same. I did a recent sight set of data by calculator, H.O. 249, and Weems 1927 (using my 1942 Book), and got exactly the same Hc and Z. For me, the calculator is the fastest method, and H.O. 249 is also very quick. Weems tables A & B are logarithms (aids to solutions) and not as intuitive, but easy to use. As stated by Greg, Weems also offers a simple equation for getting Z, and by ignoring his complicated rules for Z and just knowing the quadrant of the celestial body, it is easy to get Zn.

For someone not wanting to purchase volumes two and three of H.O. 249, consider Weems 1927 LOP Book as a second method of solution. Maybe you can find a copy at a reasonable price, as I did.

YES, I do my reductions by hand because I need to "see" the solution unfold. I make enough errors and it is easy to check(erase) results.

Bruce
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