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    Silicon Sea: Leg 65
    From: Dan Hogan
    Date: 2000 Jun 01, 2:26 PM

    Chart(s): Plotting Sheet
    Sight Reduction and
    Dead-Reckoning problem     Leg 65  060100   Test your knowledge!
    ----------------------     ------  ------   --------------------
    On 09/05/2000 {at} 14:05:13UT, with a Noon Sight(LAN), we had an Estimated
    Position of (13d 10.9'S  32d 12.7'W). We are headed for our Mid-Ocean
    Waypoint 2(MOP2) (00.00dN  30d 00.0'W) to cross the Equator. TC 009.5d,
    Speed 10.5Kts. Var 21dW, Dev 0.0dW. We have logged 504 mi since our Noon
    1)  What is the DR position?
    --  ------------------------
    2)  What is the UT Date and Time of our DR at the 504 mi?
        What is the Zone Time(ZT)?
    --  -----------------------------------------------------
    3)  What is the celestial event that occurs at about 17:57:00ZT?
    --  -------------------------------------------------------------
    4)  What is our DR position at the time of this celestial event?
    --  -------------------------------------------------------------
       Body                 UT                              Hs
       Moon LL              20:20:05                68d 01.5'
    |  UNKNOWN              20:21:10                46d 07.5'
       Arcturus             20:22:45                18d 02.2'
       Spica                20:23:30                33d 43.4'
       Miaplacidus  20:24:10                24d 15.2'
       Dubhe                20:25:30                22d 28.9'
    5)   One of the above bodies is unsuitable for a sight. Which
         body and Why?
    --  ---------------------------------------------------------
    6)   What is the name of the UNKNOWN bright Star half way up from the
         horizon bearing 270.0d by the steering compass?
    --  ----------------------------------------------------------------
    7)  What is our FIX position at the time of the first Sight Reduction?
    --  ------------------------------------------------------------------
    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{at}mtrs x 2.07; Nmi = SQRT HE{at}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{at}IMPS0014.US.DG.COM
            John Simmonds- johnsimmo---.com
            Jim Manzari  - manzari{at}bluewin.ch
            Dan Hogan    - dhhogan{at}nav.cnchost.com
    Dan Hogan
    NAV-L Web Page: http://nav.cnchost.com

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