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    Silicon Sea INTRO
    From: Dan Hogan
    Date: 1999 Jun 04, 1:01 PM

    Revised: 06/04/1999
                       THE CRUISE OF THE SILICON SEA
    Is a series of navigation problems in the form of a circumnavigation.
             published by the NAVIGATION-L LIST
    To join the list send a message with no subject and no signature to:
    On the first line of the message body:
    The Archived Silicon Sea files and Navigation Programs may be
    downloaded from http://nav.cnchost.com. There is NOT an ANONYMOUS FTP
    access available at nav.cnchost.com.
    The problems consist of voyage planning, Dead Reckoning(DR) and
    Celestial Sight Reduction. The first problem is LEG 10, which starts at
    Palma de Majorca, Spain. The cruise destination is Boston,
    Massachusetts, USA via the Suez Canal, the Southern Ocean and Cape Horn.
    Newbies, Oldbies, In-between-be's and anyone just plain interested,
    join in. The only requirement is PARTICIPATE. If you don't know, ASK on
    the Navigation-L list.
    The problems require the Nautical Almanac for the year they were
    posted, and a Sight Reduction method. There are several computer
    shareware and freeware navigation programs available that will greatly
    aid in learning and can be used instead of the Nautical Almanac.
    All other information is lifted from the DMA Pilot Charts, Jimmy
    Cornell's World Cruising Routes, and any documents and charts available
    within the working group without incurring an added expense. This is a
    navigation exercise, not a simulated voyage. There may be an occasional
    errors in some of the problems, both intentional and accidental. They
    are there to stimulate discussion by the list.
    As of the above revision date the LEGS (problems) run from Leg 10 to
    Leg 51. There is no Leg 45, it was a break in the sequence during a
    hiatus by the author of the problems.
    The problems are not copy righted. They may be used and modified as
    desired. But credit to the Navigation-L list is appreciated.
    A marine navigation reference book is recommded. Any government
    published manual or general navigation text will suffice.
    A Navigation Log Book, aka. Spiral Binder, to keep track of your
    doings. Believe me it can't be done 100% on a computer.
    The minimum tools you will need:
        1) A pencil and ERASER.
        2) Something to draw straight lines with.
        3) Something to layout angles with.
        4) Something to use as a plotting sheet.
        5) Something to calculate trig. formulas with.
        6) A current Nautical Almanac for sight reductions and sun problems.
        7) A pair of dividers.
        8) A Sight Reduction method. (229, 211, spreadsheet, etc. or...
        9) For us lazy souls, a Computer or Calculator Navigation Program
           of your choice.
       10) Plotting Sheets or a piece of paper to make a plotting sheet.
    Below is Dan Hogan's QED plotting for the financially under-privliged.
    Blatently stolen from Self Contained Celestial Navigation with H.O. 208,
    John S. Letcher, 1977, International Marine, ISBN 0-87742-082-3.
    Use lined paper, college ruled, Turn the paper 90d, so the lines are
    vertical. Ruled lines are used for longitude. Every sixth or twelfth
    line is darkened to represent a whole degree of longitude. (depending
    on the scale desired).
    Lines of latitude are added by construction, starting with the lowest
    latitude desired. Whole degrees are 60 miles.
    From your lowest Latitude line, at the most R/H longitude line, draw a
    line at an angle up from the Latitude of your lowest latitude line plus
    a 0.5d(i.e.:28.5d). For ten miles to each vertical line use 6 lines;
    for 5 miles to the line use 12 vertical lines. Where the angled line
    crosses your 6th and/or 12th line swing an arc until it touches your
    R/H vertical longitude line. This is the point of the next latitude
    line. Draw a line perpendicular to the longitude across the page.
    Repeat the process with each higher latitude (29.5d), etc.
    The bottom angle line, where it crosses the the intermediate vertical
    longitude lines, is the distance interval. 10 miles each line for 6
    line spacing. 5 miles each line for 12 line spacing. This forms a handy
    scale of miles or minutes of latitude.
    The accuracy is within the tolerance of your #2 pencil point.
    Dan Hogan
    West Covina, CA

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