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    Re: Silicon Sea Navigation Glossary
    From: Dan Hogan
    Date: 1998 Apr 06, 9:18 AM

    Buck & All:
    Here is the intro for the Silicon Sea Navigation Cruise.
    Dan Hogan WA6PBY
    "Gacha" Catalina 27
    Silicon Sea is an armchair(computer?) circumnavigation excersize.
    This version started at Palma de Mallorca, Spain. West about via the
    Indian Ocean to Boston. If I live that long ;^)
    Below are the original announcements for the cruise. Each problem is
    complete in it self, no need to have worked the previous.
    The following files are available. Due to roninhouse.com problems
    with the FTP site. I can provide them on reqyest, but be patient;
     ALMANAC.ZIP - freeware Nautical Almanac by John Simmonds
     POSPLOT.ZIP - freeware plotting sheet program by Wes Murfin
     SSCHARTS.ZIP - freeware chartletts for the Silicon Sea excersizes.
     SSNAVCRUZ.ZIP - the Silicon Sea navigation excersizes with answers
     				in a separate text file.
     The total set is about 718 Kb.
    The Cruise of the Silicon Sea
    If you want to join us, do. The only requirement is enthusiasm and
    participating in the discussions.
    The response for the resumption of the Silicon Sea cruise is
    overwhelming! The first problem is just about completed. The plan is
    to post it next week or would it be better to wait until after the
    Spring Break?
    Got caught on my first post. Obviously those doing their navigation
    the old fashioned way, working for it, will need an Almanac. This
    makes the essential tools, Almanac, Plotting tools, plotting sheet,
    and a Sight Reduction method. The dates for the problems will be
    concurrent with the Nautical Almanac. All other information will be
    lifted from charts and documents available to the working group.
    In order to save some time, and make it easier on me, the cruise
    will pick up where the old one left off, at Palma de Mallorca in the
    Mediterranean. The route is consistent with Pilot Charts for the
    time of year (although mine date from 1978).
    The Route:
    Palma de Mallorca-Isle Horadada Light(departure point)-a point at
    the entrance to the Strait of Sicily-Port Said-Transit the Suez
    Canal-Transit the Red Sea-Adan(planned stop)-Cape Lueewin-Bass
    Strait-Sydney, Australia(planned stop)-Cape
    Horn-Barbados-Boston(home port).
    Be aware this is the planned route, STUFF Happens.
    I have kept the posts sent from those joining the cruise. If I don't
    see your participation you will be asked to WALK around Cape Horn.
    Ok, time is running out Leg 10 the *FIRST* problem in the cruise of
    ronin.com's SV Silicon Sea will be out on 10/05/96.
    Newbies, Oldbies, In-between-be's and anyone just plane interested,
    join in. The only requirement is PARTICIPATE. If you don't know,
    ASK. That's why we are doing this.
    I recommend a Navigation Log Book, aka. Spiral Binder. To keep track
    of your doings. Believe me it can't be done 100% on a computer.
    Again the required tools:
        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) Nautical Almanac for sight reductions and sun problems.
        7) A pair of dividers.
        8) For us lazy souls, a Computer Navigation Program of your
    Anyone who thinks of something I missed post it to the list.
    Below is Dan Hogan's QED plotting for the financially
    under-privileged. Blatantly 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 lie 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
    0.5d(ie.: 28.5d). For ten miles to the vertical line use 6 lines;
    for 5 miles to the line use 12 vertical lines. Where the angled line
    crosses your 6th 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 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.
    The programs are currently unavailable from FTP roninhouse.com. If
    you use an ftp program or some other web browser you may need a
    program to view and print gif coded files. Freeware viewer programs
    for Windows are available at http://www.winfile.com. Contact
    dhhogan@concentric.net for Email copies that will be ZIPPED and
    UUENCODED to you. But be patient.
    There are30 Silicon Sea chart files. They cover harbors, headlands
    and coasts included in the problems. They cover the Mediterranean
    Sea, Malta to Port Said. The Red Sea, Port Said to Djibouti. The
    Indian Ocean Djuboiti,Maldive Islands,Cape Leeuwin to Sydney.
    These are minimal charts with not much more than a coast
    outline and a lat-long grid.  They are all derived from the Map
    Viewer program at Xerox PARC, http://pubweb.parc.xerox.map, with
    place names from assorted atlases and encyclopedias.  I don't have
    any access to the detailed information usually found in navigation
    charts and these might better be called "chartlettes".  They are
    still useful for providing some geographic orientation for the
    Silicon Sea cruise and if printed can be used as plotting sheets.
    For plotting you will need a course plotter or some device
    for measuring angles.  Each chart has part of the latitude scale
    graduated for measuring distance.  You need to construct a scale for
    measuring longitude but this is easy to do using the method outlined
    in Bowditch in the emergency navigation section.  You can probably
    get an accuracy of about 2 nautical miles.
    There is also a Windows program to generate and print position
    plotting sheets, posplot.zip at ftp://ftp.ronin.com/incoming.
    These sheets include a compass rose and are specific for each
    latitude. Even with the occasional jagged line of computer graphics
    they should allow an accuracy equivalent to universal plotting
    Dan Hogan
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