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Hewitt,

     The Bris is more accurate than the Kamal and behaves more like a
whole horizon sextant so it would be more practical for sun CN on a
small craft. The Kamal takes a bit of practice and good sea legs to
get trustable results. The Kamal is very useful for piloting
situations where the Bris is strictly CN. Expect accuracy to 12 derees
of altitude for the Kamal vs. the Bris which has no altitude
restrictions but seems to work better at lower altitudes.

Greg

On Jun 4, 12:57�pm, Hewitt Schlereth  wrote:
> Greg - Your device looks easier to construct than a Bris. I for one am
> following with great interest. Up to what altitude do you think it
> likely to work? �My emergency back-up has been horizon sights, which I
> used routinely whenever I found myself on deck at sunrise or sunset.
> -Hewitt
>
> On 6/4/09, Greg Rudzinski  wrote:
>
>
>
> > �I was able to test the Trombone Kamal prototype at the beach today and
> > �found that observing the sun through scotch tape and plex wasn't going
> > �to work and that an additional reference mark was needed at 3 inches.
> > �The clear scotch tape was removed and the reference marks were grooved
> > �in with a straight edge and razor blade then blackened with a felt tip
> > �pen. Three observations were successfully performed before sunset
> > �yielding �intercepts inside of 10 miles vs. GPS but more testing will
> > �need to be done to confirm accuracy. The concept is showing promise.
>
> > �On Jun 3, 10:52 am, Greg Rudzinski  wrote:
> > �> --- On Wed, 6/3/09, Greg Rudzinski  wrote:
>
> > �> > From: Greg Rudzinski 
> > �> > Subject: TROMBONE KAMAL PROTOTYPE
> > �> > To: gregrudzin...@yahoo.com
>
> > > > Date: Wednesday, June 3, 2009, 10:46 AM
> > �> > The Trombone Kamal gives the 9th
> > �> > century Kamal a 20th century facelift.
>
> > �> > How to make your own.
>
> > �> > Materials:
> > �> > - 3.5 x 5" x 1/8" white plex which is transparent enough to
> > �> > see a faint image of the sun through it at low altitudes.
>
> > �> > - Standard metal tape measure.
> > �> > - Electrician tape (black).
> > �> > - Scotch tape (clear).
> > �> > - Black felt tipped pen.
>
> > �> > 1. Lay a strip of electricians tape along the 3.5" base of
> > �> > plex. This will be the horizon reference line.
>
> > �> > 2. Using a black felt tipped pen precisely draw in lines
> > �> > spaced 1", 2", and 4" above the electrician tape horizon
> > �> > reference.
>
> > �> > 3. Place clear scotch tape over black lines to fix and
> > �> > protect from smudging.
>
> > �> > How to use.
>
> > �> > � � �Place the metal tape measure end
> > �> > centered just below the horizon reference. Hold in place
> > �> > with index finger and thumb then trombone the tape measure
> > �> > out until pressed below the eye. Adjust the tape measure in
> > �> > or out until the sun and horizon are bracketed by reference
> > �> > lines. The hs altitude will be the inverse tangent of 1", 2"
> > �> > or 4" over the tape measure reading. A K&E 4080-3 10"
> > �> > slide rule works well for this calculation.
> > �> > � � �Relative bearings, doubling the
> > �> > angle on the bow, and distance off by vertical angle are
> > �> > piloting applications that can also be performed by the
> > �> > Trombone Kamal.
>
> > > �IMG_4414.JPG
> > �> 629KViewDownload
>
> > �> �IMG_4415.JPG
> > �> 980KViewDownload
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