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    Silicon Sea SAMPLE Problem
    From: Dan Hogan
    Date: 2001 Mar 24, 12:22 PM

    There have been several requests asking what the Silicon Sea navigation
    problems are like. Below is a previous lesson, with the answers.
    Please post inquires about Silicon Sea to the list. You Oldbe Silicon Sea
    crewmen please respond with your thoughts.
    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
    1)  What is the DR position?
    --  ------------------------
    2) Based on the provided information, what is the Compass Course we are
    -- --------------------------------------------------------------------
    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?
    --  -------------------------------------------------------------------
    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=-
            (On Hold Pending Acknowledgement)
    ********************ANSWERS Leg 59 (112299)**************
    1) DR= 25d 39.3'S 45d 18.2'W
    2) CC= 49.0d
    |3) ZT= 1000Hrs.
    4) Date= 04/04/1999
    5) FIX= 24d 21.5'S  42d 55.3'W
    6) Dist= 434.5 mi
    7) CC= 239.6d
    8) Hours= 45h35m54s

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