otnmbrd wrote:
Wayne.B wrote in
news

On Mon, 06 Mar 2006 05:01:05 GMT, otnmbrd
wrote:


Gee, I wonder how I navigated all over the world, offshore, prior to
GPS, if I had no viable alternative to GPS.

Probably celestial and DR unless you were lucky enough to be on a ship
with a good inertial system.

Tell us about the times when you couldn't get a celestial fix because
of clouds.




First off remember..... you're offshore. Although it's great to know
exactly where you are at all times, for much of your trip it's not really
necessary and even when things were great for celestial you only got three
"exact" fixes every day ... morning/evening stars and noon.
Sure there are times when you don't get a fix for extended periods and
anyone can tell of cases where this caused a grounding, etc., but for the
most part you were and are able to use your knowledge of your boat's
reaction to weather, known currents, etc. to maintain a reasonable DR until
you do get a sight, come on soundings, approach land, etc.
You use whatever is there.
The problem with the sole reliance on GPS or multiple GPS is that you
become a "mechanical" navigator and either forget how to use other methods
or never learn them to begin with, which can rear up and bite you on the
butt when the bananas hit the fan.

otn
How does putting a GPS fix on the chart help you forget your boat's
reaction to weather, currents (it tells you them), DRing etc? If
anything it proves your estimated position.