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    Silicon Sea: Leg 78
    From: Dan Hogan
    Date: 2003 Jun 9, 09:19 -0700

    Chart(s): Plotting Sheets
    Sight Reduction and
    Dead-Reckoning problem     Leg 87  060903   Test your knowledge!
    ----------------------     ------  ------   --------------------
    We are bound for Mid-Ocean Point 1(MOP1)(40d 00.0'N  155d 00.0'W). Where
    we plan on changing our course toward Mid-Ocean Point 2(MOP2)
    (45d 00.0'N  124d 00.0'N).
    Our DR position was (29d 22.4'N  160d 54.6'W) on 07/09/2002 @
    20:20:30UT. TC 24.6d, Speed 10.5 Kts, Var 12dE, Dev 1dW, Current Set 035.0d,
    Drift 0.3 Kts.
    1)  What is the Compass Course(CC)/Course-to-Steer to MOP1(40d 00.0'N
        155d 00.0'W)?
    --  -----------------------------------------------------------------
    We continue on TC 24.6d, Speed 10.5 Kts, Var 12dE Dev 1dW. On the morning
    after our last DR position of(29d 22.4'N 160d 54.6'W) on 07/09/2002 @
    02:20:30UT. We manage a quick Sun sight through the broken cloud cover.
        Sun LL   Hs 27d 39.8'
    2)  What is the LHA and Declination of the SUN?
    --  -------------------------------------------
    3)  What is the Azimuth(Zn) of the SUN?
    --  -----------------------------------
    4)  Using the steering compass, what is the compass bearing to the SUN?
    --  -------------------------------------------------------------------
    5)  What is the TC and Distance to MOP1(40d 00.0'N  155d 00.0'W) from our
        Sun LOP/DR position)?
    --  ---------------------------------------------------------------------
    Speed 10.0 Kts, Current Set 273.0d Drift 0.4 Kts. Var 15dE Dev 1dW.
    6)  What is the Compass Course(CC)/Course-to-Steer to MOP1(40d 00.0'N
        155d 00.0'W)?
    --  -----------------------------------------------------------------
    7)  How many hours is it to our estimated arrival at MOP1?
    --  ------------------------------------------------------
    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
            Mike Wescott - wescott_mike@emc.com
            Dave Weilacher - daveweilacher@earthlink.net
            Tony Capiello - anthony.cappiello@baesystems.com
            Richard Berkowitz - richdberko@aol.com
            Dan Hogan - dhhogan1@earthlink.net

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