Chart(s): Plotting Sheet, leeuwin.gif, bass.gif

Sight Reduction and
Ded-Reckoning problem     Leg 40  XXXXXX   Test your knowledge!
----------------------     ------  ------   --------------------

Our DR position 19/07/1998 @ 18:00:00ZT (32d 33.2'S  113d 58.9'E).
Sky overcast, Sea moderate waves and longer; many white horses. TC
147d, speed 10 Kts, Current Set 175d Drift 6 mi per day. Var 4dW, Dev
4dW.

We take the following sights:

     Body           GMT            Hs             Zn

     Gacrux         11:10:15       57d 47.7'      211.5d
     Nunki          11:14:22       34d 44.7'      101.3d
     Peacock        11:25:30       30d 07.8'      140.9d

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

Assuming the Cape Leeuwin Lighthouse is at(34d 21.0'S  115d 05.3'E).
Its height is 56 meters and that the light can be seen for 25 miles.

2)  What is the TC and Compass Course(CC) to the Cape Leeuwin light?
--  ----------------------------------------------------------------

3)  What is the distance at which the light should be visible
    on our horizon?
--  ---------------------------------------------------------

4)  Based on our estimated SMG at what Date and Zone Time(ZT) can
    we expect to see the light on the horizon?
--  -------------------------------------------------------------

We sight a light on our horizon. After assuring it's the correct
light we alter course for the 100 fathom line, which lays 30 mi
offshore at this latitude. We follow the 100 Fathom line around Cape
Leeuwin. At 07:08:26ZT we take departure bearings of a cape and a hill
which give a departure position of (34d 50.2'S  116d 03.5'E).

Our next waypoint is Bass Strait(39d 18.0S  144d 00.0'E), between King
Is. and Cape Otway, Australia. The Var 3dw Dev 2dW, Speed 10Kts. The
Indian Ocean Pilot Chart for July shows current Set 105d Drift 6
mi/day.

5)  What is the TC and Dist to Bass Strait(39d 18.0'S  144d 00.0'E),
    our next waypoint?
--  ----------------------------------------------------------------

6)  What is the Compass Course(CC) to Bass Strait?
--  ----------------------------------------------

7)  To the nearest tenth, how many days enroute to the Bass Strait
    waypoint?
--  --------------------------------------------------------------

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
        Buck Godwin  - bgodwin@newsguy.com (Archive Files)
        Dan Hogan    - dhhogan@lightside.com

