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    Silicon Sea Leg 41 Problem
    From: Dan Hogan
    Date: 1998 May 22, 2:01 AM

    Chart(s): Plotting Sheets
       1998 Nautical Almanac
    Sight Reduction and
    Ded-Reckoning problem      Leg 41  052298   Test your knowledge!
    ----------------------     ------  ------   --------------------
    We have rounded Cape Leeuwin by following the 100 fathom line. Then
    taken departure bearings on the Australian coast which gave us a
    Departure FIX of(34d 50.2'S  116d 03.5'E) on 20/07/1998 at 04:08:29ZT.
    Our next waypoint is at Bass Strait(39d 18.0'S  144d 00.0'E). Speed
    10Kts, Var 3dW, Dev 2Dw, Current Set 105d Drift 6 miles per day.
    Clouds are solid overcast stratocumulus. The wind has veered to the
    SW. Large waves are beginning to form; white crests are more
    1)  Based on the waves we're seeing, what is the Beaufort
        wind force?
        What is the Beaufort wind speed range in knots?
    --  -------------------------------------------------------------
    2)  What Beaufort wave heights can be expected if the wind
        continues at this force?
        What is the Beaufort wave height in meters?
    --  -------------------------------------------
    We maintain our TC for 59Hrs 15Min 20Sec. But due to the sea
    conditions our speed has been 9Kts. The wind has increased to Force
    10. The storm sails have been set. There are very high waves with long
    overhanging crests. The surface of the sea is white with great patches
    of foam and visibility is affected. We Heave-to on a |TC of 245d.
    3)  What is the DR position at the time of Heaving-to?
    --  --------------------------------------------------
    4)  What is the Zone Time(ZT) at Heaving-to?
        What is the GMT at Heaving-to?
    --  ----------------------------------------
    We are hove-to for 68Hrs 21min 11sec before we decide to set sail.
    The wind has decreased and is now blowing at Force 7.
    5)  What is the DR position based on TC and Speed when
        we decide to set sail?
        What is the Zone Time(ZT) and Date?
    --  ---------------------------------------------------
    6)  Based on Q5 Ded-Reckoning what is the TC & Dist to
        Base Strait?
    --  --------------------------------------------------
    A look at our Indian Ocean Pilot Chart for July shows that we are in
    an area of NO VARIATION. Dev 2dW. Current Set 95d Drift 6 miles per
    day. Speed 9Kts. The cloud ceiling is beginning to raise.
    7)  What is the Compass Course(CC) to Bass Strait?
    --  ----------------------------------------------
    While we are setting sail the navigator takes a LAN sight of
    the Sun Lower Limb, Hs 32d 48.1'.
    8)  What is the Noon latitude?
        Which direction is the navigator facing during his sight?
    --  ---------------------------------------------------------
    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
    Dan Hogan WA6PBY
    "Gacha" Catalina 27
    San Pedro, CA
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