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THE CRUISE OF THE SILICON SEA (RETURN)

The Silicon Sea cruise is a series of navigation problems in the form of a
circumnavigation. The navigation problems follow a route around the world(see
below).

Newbies, Oldbies, In-between-be's and anyone just plain interested, join in.
The only requirement is PARTICIPATE. If you are new to navigation, ASK
questions
on the list. This is a learning exercise for all of us. This set of problems
will
start in April at the latest. The tentative schedule of posts will  be the
the first
and third wednesday of the month.

This portion of the Silicon Sea cruise will start with Leg 69, approaching
Bridgetown,
Barbados. Bridgetown is scheduled as a refitting point for the trip to the
Panama
Canal, HawaII, and San Pedro CA(Home Port).

Obviously those doing their navigation the old fashioned way, working for it,
will
need a current Nautical Almanac and Sight Reduction method. The dates for the
problems will be concurrent with the current (2001) Nautical Almanac. Leg 69
will require using the year 2000 Nautical Almanac. However, the problems can
be worked with computer navigation programs or calculators.

All cruise and navigation information will be lifted from the DMA Pilot
Charts, Jimmy Cornell's World Cruising Routes, and any documents and charts
available within the working group without incurring added expenses. This is
a navigation exercise, not a simulated virtual voyage.

THE ORIGINAL ROUTE:
Mallorca, Spain; Valleta, Malta; Port Said; Transit Gulf of Suez and Red Sea;
Adan, Yeman; Maldive Islands; Cape Leeuwin, AU; Bass Strait, AU; Sydney
Harbor, Australia; Wellington, New Zealand; Cape Horn;

CURRENT NEW ROUTE:
Barbados; Panama Canal; HawaII; San Pedro, CA (home port). Be aware this is
the planned route, STUFF Happens.

NAVIGATION TOOLS:
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.  A navigation
reference text is recommended. Which ever text is issued by your local
government is satisfactory.  There are many commercial volumes as well.

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.

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 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 WA6PBY
C27 "Gacha"
dhhogan@verimail.com
Nav-L Page: http://www.wa6pby.com

   

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