Gary wrote:
otnmbrd wrote:

That same bolt of lightening will take out your calculator so you
then have to work stars long hand. It'll also kill your digital
watch and radio so you won't have the correct time. It'll probably
short out your boat so you won't be able to work the stars out until
light the next morning. The lightening excuse to learn astro is BS.
Learn it because you want to or take a couple extra handheld GPS.
Practice dead reckoning. Know where you are all the time.

Gaz



Let's see...... calculator gone, long hand star calc's....add a minute
or two to the solution.
digital watch killed..... in that case I'm probably dead too so what
do I care.... always have a mechanical clock that you know the
error...no big deal, was done for years.
lights out?....lite a candle or wait till daylight.... what the hell,
it's offshore navigation, what's the rush....

And how did you check the error on that deck watch? Radio? What was the
error and how much does it change daily? Can't just do the time check
anymore. Damn lightening.

With all due respect Gary, I think you need a refresher course on
celestial. I wear a "windup" watch, and have two windup ship's
clocks. All of them are accurate to a minute a month, and have a
pretty consistent error rate. I generally set them once a week, so the
error is well under a minute. So, would you care to tell us what the
expected error would be for both Latitude and Longitude?

To be honest, I don't really buy the lightning argument either. But
I'm not sure some find fault in celestial because it is not accurate
to 3 meters.

On 6 Mar 2006 01:57:10 -0800, "purple_stars"
wrote:

except that i could use
the opportunity to listen to the slow speed morse code, i'm still
learning CW/morse and haven't been practicing!

Are you familiar with the W1AW code practice sessions? You should
have no trouble picking them up on your ICOM.

http://www.arrl.org/w1aw.html#w1awsked

On Mon, 06 Mar 2006 13:19:41 -0500, Jeff wrote:

I generally set them once a week, so the
error is well under a minute. So, would you care to tell us what the
expected error would be for both Latitude and Longitude?

A one minute error in time translates to about a 15 mile error in
longitude at the equator.

If using a noon site to determine latitude, a 1 minute error is almost
inconsequential.

This was all vitally important 20 years ago but the world has changed.

and to think i thought one minute = one minute.

otnmbrd wrote:
Gary wrote in
news:uuQOf.109032$B94.27750@pd7tw3no:


And how did you check the error on that deck watch? Radio? What was
the error and how much does it change daily? Can't just do the time
check anymore. Damn lightening.




Most watches/clocks are fairly consistent in their rate of error.
Prior to your loss of electronics you would have/should have been
maintaining a log of the watch/clock you would use for this type emergency
so that you would know not only it's error but daily rate.
You apply this error and daily rate to your calculations.

otn
Just my point, but who actually is doing this? Thank goodness for the GPS.

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.

On 6 Mar 2006 13:58:07 -0800, "Da Kine"
wrote:

and to think i thought one minute = one minute.

No. One minute = 1/60th of an hour.

In an hour earth rotates through 900 nautical miles at the equator.

1/60th of 900 = 15 nautical miles.

If your time is off by 1 minute, your east/west distance (aka
longitude) is off by 15 nm.

Issues?

On Mon, 06 Mar 2006 23:49:12 GMT, Gary wrote:

I don't miss the days where I wound the
deck watches the same number of turns at the same time every day and
gently put them away in their little gimballed boxes until the next day.
I certainly don't do it on my boat.

And neither is anyone else.

Wayne.B wrote:
On 6 Mar 2006 13:58:07 -0800, "Da Kine"
wrote:


and to think i thought one minute = one minute.


No. One minute = 1/60th of an hour.

In an hour earth rotates through 900 nautical miles at the equator.

1/60th of 900 = 15 nautical miles.

If your time is off by 1 minute, your east/west distance (aka
longitude) is off by 15 nm.

Issues?

I guess Mr Da Kine better stick to navigating by clouds!

Wayne.B wrote:
On Mon, 06 Mar 2006 23:49:12 GMT, Gary wrote:


I don't miss the days where I wound the
deck watches the same number of turns at the same time every day and
gently put them away in their little gimballed boxes until the next day.
I certainly don't do it on my boat.


And neither is anyone else.

The voice of reason!