Chart(s): Plotting Sheet

Sight Reduction and
Dead-Reckoning problem     Leg 59 |112299   Test your knowledge!
----------------------     ------  ------   --------------------

Our Last DR position was (49d 40.7'S 62d 20.0'W) on 29/03/1999 @ 1800ZT. We
have been traveling under a solid overcast for days. TC 29.6d, Speed
10.3Kts, Current 0.8Kts Set 20.0d. Var 19dW Dev 1dW. Log distance is 1648
mi. We are bound for a waypoint at Rio de Janerio, Brazil (30d 00.0'S 48d
00.0'W).

1)  What is the DR position?
--  ------------------------

2) Based on the provided information, what is the Compass Course we are
    steering?
-- --------------------------------------------------------------------

The GMT/UT is 1300.

3)  What is the Zone Time(ZT)
--  -------------------------

4)  What is the Date?
--  -----------------

That evening we manage a round of sights.

    Body                    GMT         Hs
   Venus                    21:30:00    14d 43.7'
   Rigil kentaurus          21:33:04    13d 31.1'
   Achernar                 21:35:11    21d 55.4'
   Hadar                    21:37:02    17d 55.4'


5)  What is the FIX position?
--  -------------------------

6)  What is the distance to the Rio waypoint?
--  -----------------------------------------

The current, according to the Pilot Chart, Set is 23d, Drift is 0.8Kts.
Speed 10.3Kts. Var 21dW, Dev 1dW.

7)  What is the Compass Course(CC)/Course-to-Steer?
--  -----------------------------------------------

8)  To the nearest minute, based on Q7 data, how many hours are we from
    the Rio waypoint?
--  -------------------------------------------------------------------

NOTE:
Lat & Lo = XXd XX.X', Date=DD/MM/YY, HE 9 Feet, Index correction
-2.5', Time hh:mm:ss in UT,unless otherwise stated. Silicon
Sea II is a 34,000 lb(15.40t) displacement sailing vessel, 48' 3"
(14.70m) LOA. 39' (12.00m) LWL; Cutter rigged. Can tack to 45d.
Water Tanks = 220 gal(1000 ltrs). Fuel Tanks = 155 gal(700 ltrs).
Fuel consumption .675 gal/Hr at 8.5 Kts. DR(Ded-Reckoning)=position
by sailings, EP(Estimated Position)=DR+current affect. Dist to
Horizon: Nmi = SQRT HE@mtrs x 2.07; Nmi = SQRT HE@ft x 1.17.

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@IMPS0014.US.DG.COM
        John Simmonds- johnsimmo@bigpond.com
        Jim Manzari  - manzari@bluewin.ch
        Dan Hogan    - dhhogan@nav.cnchost.com

Dan Hogan WA6PBY
C27 "Gacha"
dhhogan@nav.cnchost.com
Navigation-L: http://nav.cnchost.com

