DR and Sight Reduction     Leg 11  042496   Test your knowledge!
----------------------     ------  ------   --------------------
We are at the end of our first day of the voyage. At our DR at
19-14-30 of (39d 02.7'N 4d 19.9'E). Sailing almost downwind.
Everyone is anxious to start REAL navigation. So as soon as it
gets dark out comes the sextant for a round of star sights. Being
as we are in the Mediterranean, the skipper knows it is hard to get
seriously lost here. He limits the activity to 3 stars. 

Distance Off(D OFF) is the minutes differance between the DR and the
Fix and the azimuth(Zn).

  Body		  GMT		  Hs		     Zn

 Procyon	     19-11-30	     36d 22.0'	     243d
 Spica		19-13-10	     27d 47.4'	     134d
 Alioth		19-14-30	     63d 08.8'	     40d


1)  What is the Fix position, Using 19-14-30?
    What was the D OFF?
--  -----------------------------------------------------

With our Fix at hand. We plot our new course to our point
at the Strait of Sicily(38 30.3N 10 42.0'E)

2)  What is the TC and Dist to the Strait Of Sicily?
--  ------------------------------------------------

The wind has picked and is now blowing at 15 Knots from 285d. 
We are on a downwind run. Our speed has increased to 7.5 Kts. 
At 02-44-30 we are at DR(38d 56.2'N  5d 34.1'E)

3)  Using the current DR at what ZT does MNT occur ?
--  ------------------------------------------------

4)  How many more miles will we have traveled at this MNT?
    What is this DR?
--  -----------------------------------------------------

5)  What is the brightest body available at MNT?
    What is its Hs and Zn?
--  -----------------------------------------------------

In these days of 16 digit readouts it's hard to remember that 
Navigation is an art. Put ten navigators on the same problem 
and you get 10 different answers. Especially when each one is 
using a differnt method. So if you're on the chart in the 
general area of your DR you aren't lost. 

We are sailing through the sea that was the birthplace of 
naviagtion. The Galleys of the Phoenicians and Greeks plyed 
these waters. The first direction indicators were wind lines 
with the names of winds for direction. In time the winds were 
standardized to 32 names. Then with the introduction of the 
magnetic compass, these wind names were altered to fit 
navigating with it. In modern times these became N NE E with 
further divisions so that there were a total of 32 points of 
referance. Now we use the simple 360d compass card.

6)  What is the angle of one Point on the compass?
--  ----------------------------------------------

The local variation is 2dW. Our compass Deviation is 4dE.
Current Drift is 0.5Kts, set 225.0d.

7)  What is the the Compass Course(CC) to the Strait of Sicily? 
    What is the procedure for going from a TC to Compass Course(CC)
     called? 
    What is the acronym for this procedure?
--  ----------------------------------------------------------------

8)  How many hours will it be until our arrival at
    the Strait of Sicily?
--  -----------------------------------------------

Note:
     Lat & Lo = XXd XX.X', Date=DD/MM/YY, HE 8 Feet, Index correction
      -.2', Time hh-mm-ss in UTC/GMT. Silicon Sea is a medium 
     displacement sailing vessel, 40 Feet LOA. 38 Feet LWL; Cutter 
     rigged. Looks a lot like a Mason.

PLEASE respond with your results and thinking on these exercises POST
to the NAVIGATION list at large. If you have questions or problems,
A lot of folks on the list are knowledgeable and willing to help. 
Any questions or doubtful areas will be responded to promptly. Let 
us hear from you soon!

Good Navigating!

   -=The Navgation List Working Group=-

