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    Leg 83
    From: Peter Fogg
    Date: 2002 Sep 22, 13:52 +1000

     Q1)          navigator (9ft) to horizon      3.51nm
    Mauna Loa (4169m) to horizon         +133.66 nm
          navigator to top ML on horizon    137.2 nm
    
    Q2) First calculate TC along rhumb line from (N18d 37'.2  W152d 13'.6)
    to (N19d 30'.0  W155d 36'.0)
           by MP&MD  285.3d
               MP           285.3
           PS (ML)        285.4
           by plot          285d
    
    Then, by plotting, with fast speed and weak contrary current,  I get CMG
    286d and SMG 9.3k,
           thus TC to steer  284d
    combined error     E   -11d
    CC to steer                273d
    
    Q3) Time Zone at (W150d +/- 7.5d) is West 10 hours, 10 hours behind UT.
    
    Q4) traverse from N18d 37'.2   W152d 13'.6    at 290d  for 140 nm.
           MP&MD       N19d 25'.3   W154d 32'.5
            ML              N19d 25'.1   W154d 32'.0
            plot              N19d 24'      W154d 31'.5
    
        elapsed time is 140 nm / SMG 9.3k = 15h 03m 14s
    
    Q5) Am a little unsure what is meant to be done here, assume what is
    needed is the CC to steer from
        calculated DR (N19d 25'.3  W154d 32'.5) to DO point (N19d 30'.0
    W154d 41'.6).
        First calculate TC along rhumb line   (distance
              MP&MD 298.6d                           9.8 nm
                MP       298.5                             9.8
             PS(ML)   298.7                             9.8
                plot      299.0d                          12.0 nm - from
    plotted DR)
    
        Then another vector diagram, this time with current setting to the
    west. TC to steer 300d
    
    combined error     E   -11d
    
    CC to steer                289d
        elapsed time is 9.8 nm / SMG 10.5k = 00h 56m 00s
    
    Q6) rhumbline calculation for distance from (N19d 30'.0  W154d 41'.6)
    to (N19d44'.0  W155d 04'.0)
        by MP&MD  25.3 nm
             MP          25.4
             PS (ML)  25.3
                 plot     25.8
    There is no information on current for this leg so shall assume speed is
    10k.
    elapsed time is 25.3nm / 10k = 02h 31m 48s
    
    
    Q7)     For the ETA at Hilo add the time for each leg to   01:44:36 UT
    on 16/07/2001
    
    + 15:03:14
    
    + 00:56:00
    
    + 02:31:48
    
    = 20:15:38 UT on 16/07/2001
    
    = 10:15:38 ZT on 16/07/2001
    Notes:
    MP&MD     Meridional Parts and Meridional Distances
    MP             Meridional Parts
    PS (ML)      Plane Sailing (Middle Latitude)
    As all the distances involved in these rhumb line and traverse
    calculations are fairly short ones in low latitudes there is little
    difference between the different calculations.
    
    
    

       
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