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You
Really Need To Know This
(
the art of coastal navigation )
It’s a strange
thing about sailing.
Figure this.
It’s much easier
and safer to navigate your boat over thousands of miles of untracked
ocean, from say Seattle to Tokyo, than to sail 5 miles into the
harbour of any city at night - or 20 miles along any coast for that
matter, day or night.
You can blame
it on technology of course. The Global Positioning System, or GPS,
has made ocean navigation relatively simple. Press a button and
you know where you are to within a few meters.
And when you
navigate in oceans you’re generally headed for a fairly big target,
a city or major port, so there really isn’t the need for the pinpoint
position accuracy you get with GPS. Unless of course you’re sailing
into the reefs and atolls of the south pacific, in which case you’re
in the same trouble as
the
coastal navigator
Most problems
in navigation come when you get to the rocky bits around the edge.
If you’re sailing
on a shoestring as many of us are, you’re probably using paper charts
and a GPS for navigation. But have you checked the date that your
chart was surveyed recently?
If you do, you’ll
probably find that the actual survey the chart is based on was done
way before they had GPS, maybe even a hundred years ago.
And herein lies
the problem.
Your GPS will
give you a position within 10 meters, but your chart may be nowhere
near that accurate, especially if it’s a chart of some unfrequented
coast.
So if you rely
on your GPS for position and lay that position on your paper chart
and then believe what you see on the chart, you could be in for
an unpleasant surprise.
You should always
assume that the indicated positions of offshore reefs, rocks, sandbanks
and other nautical obstacles are at best approximate when you lay
a course on your paper chart. You should also realise that your
chart has probably not had a major revision for 50 years.
Things change
- and
it probably wasn’t that accurate in the beginning.
What I’m coming
to is a plug for the ancient art of coastal navigation.
I believe every
sailor who ventures outside his or her port or estuary should have
a working knowledge of coastal navigation.
Relying on your
GPS is not sufficient.
You need to
be able to keep a dead reckoning log, you need to be able to check
your position using a depth sounder, a hand-held compass, dividers
and parallel ruler, you need to be able to interpret your chart
and use the information on it to help you determine your position.
In other words,
you need to become a coastal navigator.
Your life could
depend on it.
Why not get
this vital skill before the next sailing season?
Here’s my pick
of the coastal navigation courses available on the internet. I don't
know this guy, but he's based in my home state, South Australia
and the multimedia course is really very good.
Don’t be put
off by the hokey website.
Tony
Hollin's multimedia coastal navigation course
And I don’t
make a cent out of this recommendation - unfortunately
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