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    Re: New to list. Request info.
    From: Dan Hogan
    Date: 1997 May 14, 18:11 EDT

    Welcome to all newcomers to the list. Below is the information regarding
    the Silicon Sea navigation problems. Also browse both FTP:
    ronin.com/incoming and the /navigation for programs and navigation data.
    Also visit http://www.ronin.com.
    Dan Hogan WA6PBY		Yacht GACHA
        West Covina, CA		Catalina 27
        dhhogan@XXX.XXX	San Pedro, CA
    Silicon Sea is an armchair(computer?) cicumnavigation 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 Cruise of the Silicon Sea
    If you want to join us, do. The only requirement is enthusiasm and
    participation 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 choice.
    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
    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.
    Silicon Sea Chartletts Info
            Charts for upcoming legs of Silicon Sea have been posted at the
    Ronin ftp site.  They can be downloaded  by ftp or with a web browser using
    the URL ftp://ftp.ronin.com/incoming.  This is easy to do with Netscape.  It
    automatically displays the graphic file and you may be able to print it
    directly from Netscape.  If you use an ftp program or some other web browser
    you may need a program to view and print gif coded files.  A freeware viewer
    program for Windows is also available at ftp.ronin.com/incoming under
    lview.zip.  The Silicon Sea chart files are:
            egypt.gif     - approach to Egypt
            portsaid.gif  - Masabb Dumyat to Port Said
            suez.gif      - Suez canal
            gulfsuez.gif  - Gulf of Suez with charted lighthouses
            redsea1.gif   - Red Sea, lat 28N to 25N
            redsea2.gif   - Red Sea, lat 25N to 22N
            redsea3.gif   - Red Sea, lat 22N to 19N,
                              Port Sudan and Jeddah
            redsea4.gif   - Red Sea, lat 19N to 16N
            redsea5.gif   - Red Sea, lat 16N to 13N
            redsea6.gif   - Bab el-Mandeb Strait
            aden.gif      - approach to Aden harbor
            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 usefull 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 sheets.
    Dan Hogan
        West Covina, CA
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