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    Silicon Sea: Leg 78
    From: Dan Hogan
    Date: 2001 Aug 29, 7:52 AM

    Is there anyone out there that is still interested in the Silicon Sea
    navigation cruise. It seems that all the people that post answers/questions
    on Silicon Sea are now members of the working group.
    If there is no one willing to work/discuss it then there is not much point in
    continuing the problems.
    *********************Cut Here*********************************
    Chart(s): Plotting Sheets
    Sight Reduction and
    Dead-Reckoning problem     Leg 78  082901   Test your knowledge!
    ----------------------     ------  ------   --------------------
    Our last FIX was (03d 20.7'N 080d 27.2'W) on 25/06/2001 @ 22:45:23UT. The
    electronic log on the Knotmeter was re-set to 000.0. We are bound for a
    Mid-Ocean Point(MOP1) at (030d 00.0'N 110d 00.0'W). It is a turning point
    that is recommended by most ocean passage Sailing Guides for a passage from
    Panama to Hawaii.
    There are high Mares Tails clouds moving in from the Northwest. The
    Barometer has fallen slightly. The clouds are increasing. Speed 10.5 Kts, Var
    0.0d Dev 1.5dE. Current Drift 0.6 Kts, Set 350d.
    1)  What is the TC we are on?
        What is the Compass Course/Course-to-Steer?
    --  -------------------------------------------
    At a distance log reading of 116.5 Nmi since our last position FIX
    (03d 20.7'N 080d 27.2'W) on 25/06/2001 @ 22:45:23UT we take the following
    three sights through openings in the clouds.
    Var 3dE Dev 1.5dE
        Body        UT/GMT          Hs
        Venus       10:51:10        36d 31.6'
        Unknown     10:53:30        31d 53.8' Compass Bearing 276.5d
                                           (Moderately bright)
        Fomalhaut   10:57:11        55d 21.7'
    2)   What is the DR position at the time of the Venus sight?
    --  --------------------------------------------------------
    3)  What is the FIX position?
    --  -------------------------
    4)  What is the name of the unknown body?
    --  -------------------------------------
    We expect to enter the South Equatorial Counter Current at about 03d 00.0'N
    095d 00.0'W.
    Var 3dE, Dev 1.5dE. Speed 10.0 Kts. Drift 0.6 Kts, Set 295d.
    5)  From our last FIX position with the log reading of 116.5 Nmi, what
        is the distance the Knot Log should read at (03d 00.0'N  095d 00.0'W)? --
    6)  What is the UT/GMT date and time of our Estimated Time of Arrival(ETA)
        at the Counter Current Point?
    --  ----------------------------------------------------------------------
    7)  What Compass Course(CC)/Course-to-Steer are we steering?
    --  --------------------------------------------------------
    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     - Smith_Peter@EMC.COM
            John Simmonds   - johnsimmo@dingoblue.net.au
            Tony Cappiello  - cappiello@kearfott.com
            Frank Norris    - NORRIS_FRANKLIN_H@LILLY.COM
            Sam Chan        - schan@socal.rr.com
            Mike Wescott    - wescott_mike@EMC.COM
            Dan Hogan       - dhhogan@veriomail.com
    Dan Hogan

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