NOTE to SS'rs:

It has been pointed out that I have taken too many short cuts in 
my effort to ease my work on Silicon Sea. So back to basics. The
current data provided on a Pilot Chart is the average velocity in 
miles per day. I will state them in either as "Pilot Chart 260d 
8m" or for a specific problem as "Set ddd, Drift .xx Kts/Hr."


Chart(s): Plotting Sheet

Sight Reduction and 
Dead-Reckoning problem     Leg 38  XXXXXX   Test your knowledge!
----------------------     ------  ------   --------------------

On 14/07/1996 @ 12:21:28ZT our Lat was 14d 41.1'S, EP Lon was
101d 07.1'E. TC was 125.4, Speed 10 Kts, Var 4dW, Dev 4dW. Sky still
overcast. It was obvious that we had missed Cocos/Keeling Island(12d 02.0'S
97d 00.0'E).

1)  What is the TC for Cape Leeuwin(34d 15.0'S  115 06.0'E) from the
    Estimated Position(14d 41.1'S 101d 07.1'E)? we estimate current 
    Set 260d Drift .33 Kts/Hr
--  -----------------------------------------------------------------

We continue on the TC to Cape Leeuwin. At 18:21:28ZT(Zone Time) we take 
a sight of a bright body between a break in the clouds.

	Hs		 Compass Bearing
	58d 49.3'	 100.9d

2)  Excluding Current, what is the DR position to use for the Sight 
     Reduction?
--  ----------------------------------------------------------------

3)  a) What Celestial Body is this?
    b) What its Zn?
--  -------------------------------

|4)  Using the 12:21:28ZT Estimated Position and TC, the 18:21:28ZT Body 
    LOP, what is the 18:21:28ZT DR?
--  --------------------------------------------------------------------

According to our Pilot Chart of The Indian Ocean for July, the average
*daily* current in our area is, 260d 8m.


|5)  Based on the Pilot Chart data, what is our current estimated 
    Speed Made Good(SMG) on our TC to Cape Leeuwin?
--  -------------------------------------------------------------

6)  What is the Compass Course to Steer?
    ------------------------------------

7)  At this SMG how many days(nearet tenth) is it until we reach 
    Cape Leeuwin?
--  ------------------------------------------------------------

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. Can tack to 45d. Dist to Horizon: Nmi = SQRT HE@mtrs x
2.07; Nmi = SQRT HE@ft x 1.17. Water Tank = 60 gal(Imp.). Fuel Tanks = 90
gal (Imp.). Fuel consumption .450 gal/Hr at 8.3 Kts.

PLEASE respond with your results and thinking on these exercises 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 Navigation List Working Group=-

        Peter Smith  - psmith@wellspring.us.dg.com
        Ron Legere   - ronald.legere@yale.edu
        Tony Severdia- anthonys@pacbell.net
        Wes Murfin   - wmurfin@onslowonline.net (Cartographer)
        John Simmonds- mobi@netconnect.com.au
        Jim Manzari  - manzari@bluewin.ch
        Dan Hogan    - dhhogan@lightside.com
        
