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Touche', Lu. I dig.  Hewitt

On 6/4/10, Lu Abel  wrote:
>
> Hewett:
>
> I suspect there are many more small boat sailors who still use their
> compasses than small boat sailors who are up and underway by dawn so they
> can check their compass's accuracy by pointing their boat at the rising
> sun...
>
> Lu Abel
>
> ________________________________
> From: Hewitt Schlereth 
> To: NavList@fer3.com
> Sent: Fri, June 4, 2010 8:10:40 AM
> Subject: [NavList] Re: Amplitudes
>
>  This is in the FWIW category:
>
> During the years I compensated compasses, I learned that small-boat
> sailors would become aware when their compasses were 10� out of whack.
> Some would catch on at 5�.
>
> To give small-boat sailors a rough and ready way to check their
> compasses, I developed a table of the sun's true bearing at dawn.
>
> What I did was peg declinations to their dates and apply the amplitude
> for that declination to produce the true bearing at sunrise on that
> date.
>
> True bearing at sunset is found by subtracting the sunrise bearing from
> 360�.
>
> I know that nobody uses a compass much any more, but perhaps a few
> dyed-in-the wool Luddites may find it of interest.  :-)
>
> Hewitt
>
> On 6/3/10, Greg Rudzinski  wrote:
> >
> >
> > Jeremy,
> >
> > I seem to remember that you are using an NC - 2 Tamaya navigational
> > calculator. If the LOP function on the NC -2 displays azimuths in degrees
> > and minutes (like the NC-77) then the navigator can be tricked into
> > misreading 000.55 on the display as half a degree instead of 000.92
> degrees.
> > I have made this mistake many times. My Palm program displays azimuths in
> > degrees and tenths which I like better. This could be the source of your
> > amplitude /azimuth discrepancy.
> >
> > GRudzinski
> >
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