Why Celestial
Navigation?
FOR ELECTRONIC
BACK-UP
GPS is wonderful. World-wide coverage
and reasonably priced receivers (both installed and handheld) contribute
to maritime safety through accurate positioning of vessels. Yet, some back-up
is needed.
Instances of electronic failure,
total electric failure, lightning strike, and flooding are often documented.
Even battery powered handhelds can be rendered inoperable in these ways.
Batteries can run down, spares can be lost. The GPS system itself is not
guaranteed to always be in operation.
The best possible primary/back-up
system combinations have these four characteristics in common:
-
They have independent power supplies.
-
They receive data from different sources.
-
Each system verifies correct operation
of the other.
-
The back-up system is used - not left
dormant until needed.
Celestial / electronic is the only navigation
combination that meets these requirements.
FOR MAINTAINING
SKILLS
GPS will track your boat, steer your
boat, and wake you up in the morning. Some say it will even take your boat
across the ocean for you. Without establishing a discipline, one's navigational
skills (and for that matter helmsman skills) will be jeopardized. The key
to safe passagemaking navigation is the time-proven DR track. It should
be maintained and updated with fixes, whether electronic or celestial.
This yields valuable information about current set and leeway, and steering
and compass errors which will be needed in the event of a navigational
emergency.
A good discipline to establish involves
turning off the GPS for extended periods of time (except for periodic checks),
and navigating celestially. This hones navigational skills, yields the
desired DR track, verifies correct GPS operation, and keeps your back-up
system tuned, verified, and ready to rely on if needed. Your reward will
be a well kept chart and log, an understanding of the forces affecting
your passage, and pride in navigational accomplishment.
FOR TRADITION
Tradition is not for everyone. There
are pragmatists who reject unnecessary activities out of hand. Yet most
professionals revere the traditional as well as the modern.
Who can contemplate an 18th century
brass and ebony sextant and not wonder what it was like to peer through
it at the heavens, and bring an evening star down to a twilight horizon
from the deck of a tall ship? To sense the approval of those who witness
this magic-like prowess. To triumph at a land-fall well predicted? To know
he can navigate any ocean with no help from anyone?
The sextant (and its predecessors)
is central to the history and tradition of sailing. Its image is used in
logos, letterheads, and media publicity however connected with sailing.
Authors appear with them on dustjackets. Good sailors appear with them
on deck.
FOR ENJOYMENT
Fun is doing something that is both
easy and difficult. Easy to get started with, like playing chess or hitting
a golf ball; but having enough depth that mastery does not come easily.
What could be easier than reckoning
the longitude by simply observing the time of sunrise or sunset, or steering
by a star? Almost as easy is the finding of latitude at noon. But how about
identifying the navigational stars? Recognizing the planets? Accounting
for the parallax of the moon? More experienced celestial navigators can
use an unknown star shot through a hole in the overcast, shoot planets
in broad daylight, predict sunrise underway, and calculate great circle
distances.
Being familiar with the night sky
is like having a giant roadmap overhead. One star may be over London, another
the Azores, and the moon over San Juan. All showing relative distance and
direction from you. It connects you back to the world in a way that diminishes
the sensory deprivation of a featureless sea.
People enjoy using sextants; even
from a backyard with an artificial horizon. It's one of the few nautical
activities that can be done without a boat, or even getting to the water.
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