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Subject: Silicon Sea navigation
From: Dan Hogan (dhhogan1@XXX.XXX)
Date: Wed Sep 11 2002 - 09:37:43 EDT
THE CRUISE OF THE SILICON SEA (RETURN, AGAIN)
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). archives for the navigation problems (Legs) are available for
download at -- http://www.wa6pby.com/ -- under Silicon Sea file ssea.zip.
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 83, approaching
Hilo, HawaII. Final home port is San Pedro, CA.
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 Leg 83 will be with the (2001) Nautical Almanac. Leg 84 will
require using the year 2002 Nautical Almanac. However, the problems can be
worked with any computer navigation program or nav calculators.
All cruise and navigation information will be lifted from the 1973 +/- 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 PLANNED 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, Rio de Janerio.
FINAL ROUTE WAS:
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
West Covina, CA
Owner Navigation-L List
dhhogan1@XXX.XXX
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