Wayne.B wrote:
On 5 Mar 2006 08:11:31 -0800, "Da Kine"
wrote:


If someone goes off shore with the hopes that GPS is going
to do it all for them then sooner or later, they will lose their boat
and maybe their life.


That is nonsense.

I sort of agree. The vast majority of bozos out there never lose a
boat. But, relying completely on GPS does increase your odds of
misadventure. Those who habitually employ alternatives are safer.


There is no viable alternative offshore

It isn't "offshore" that's important. You can be 50 miles off course
in the middle of the ocean without problem; its only when you approach
land that there is an issue.


other than celestial, and even
the Navy has stopped teaching it.

Urban Myth. Of course they still teach it, and its required for many
majors. I'm sure, however, that they do not spend as much time on it
as they used to.



A couple of spare GPS handhelds with some extra batteries and you are
as secure as it gets these days. You DO need to know how to use them
of course.

On this I think you're dead wrong in piloting situations. I'm not
saying I'd throw away my GPS (or the spare) but only a fool ignores a
depth sounder, compass bearings, log, radar, etc.

On Sun, 05 Mar 2006 21:42:58 -0500, Jeff wrote:

On this I think you're dead wrong in piloting situations. I'm not
saying I'd throw away my GPS (or the spare) but only a fool ignores a
depth sounder, compass bearings, log, radar, etc.

Of course, indispensible for coastal piloting.

The original statement that I rebutted was that "no one should rely
solely on GPS when OFFSHORE".

Where I come from offshore means off soundings, and the only thing you
will see on your radar is other boats.

Dead reckoning is fine but after several days OFFSHORE you will be
lucky if your DR plot is within 10 miles of actual.

I stand by my statement, there are no viable OFFSHORE alternatives to
GPS.

Wayne.B wrote in
:

On Sun, 05 Mar 2006 21:42:58 -0500, Jeff wrote:

On this I think you're dead wrong in piloting situations. I'm not
saying I'd throw away my GPS (or the spare) but only a fool ignores a
depth sounder, compass bearings, log, radar, etc.

Of course, indispensible for coastal piloting.

The original statement that I rebutted was that "no one should rely
solely on GPS when OFFSHORE".

Where I come from offshore means off soundings, and the only thing you
will see on your radar is other boats.

Dead reckoning is fine but after several days OFFSHORE you will be
lucky if your DR plot is within 10 miles of actual.

I stand by my statement, there are no viable OFFSHORE alternatives to
GPS.



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

otn

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.

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

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.

Gary wrote in
news:EN3Pf.111703$H%4.77487@pd7tw2no:


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.



Sure it tells you what, but it doesn't tell you why. Hey, good short term
plan, the GPS says steer 270..... course, this could mean you'll fight the
currents/winds , rather than use them: drive over that rock.....
GPS is a tool and all too many consider it the ultimate tool. It's not and
all too many get into the habit of forgetting to question the "why" of what
it says.
BTW, the GPS doesn't tell you your boat's reaction to weather, currents.
It's telling you your reaction to the cumulative conditions you are in.
YOU have to figure out your boats reactions to weather, currents.


otn

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
Although a yachtie or freighter may not have cared where they were all
the time, that was not everyone's attitude. Take a military example
where you have to rendezvous with another ship or submarine in mid
ocean. A few miles could mean disaster. Take the search and rescue
problem. Same thing. What about the research done on specific things
on the bottom? GPS has facilitated accurate navigation to a degree that
was only dreamed of in the past. It should be your first line piece of
kit when offshore, not at the exculsion of anything else but certainly
head and shoulders above all the rest.
In my opinion the only better way to navigate is by visual fix or radar
fix. Even then I check the fixes against GPS.

Gaz

Gary wrote in
news:uTiQf.133119$B94.26881@pd7tw3no:

Comments interspersed:

Although a yachtie or freighter may not have cared where they were all
the time, that was not everyone's attitude.

Wrong. A "yachtie or freighter" ALWAYS care where they are at all times.
The difference/arguable point is that precise knowledge to a small
amount of feet or meters is not always important.

Take a military example
where you have to rendezvous with another ship or submarine in mid
ocean. A few miles could mean disaster.

This was done on a regular basis for years prior to GPS....GPS just
makes it easier and to a degree, more positive.

Take the search and rescue
problem. Same thing.

See above, but frequently the GPS saves precious time.

What about the research done on specific things
on the bottom?

I am still amazed by the general accuracy of that research, done prior
to GPS.

GPS has facilitated accurate navigation to a degree
that was only dreamed of in the past. It should be your first line
piece of kit when offshore, not at the exculsion of anything else but
certainly head and shoulders above all the rest.
In my opinion the only better way to navigate is by visual fix or
radar fix. Even then I check the fixes against GPS.

Gaz


No one argues the value of GPS. I frequently mention shipboard
procedures, fully realizing that some things acceptable on a ship are
not acceptable on a smaller cruising vessel, since the space available
for backup and more importantly electrical power sources is considerably
different.
Personally, I'm still using GPS as my backup to check my visual/radar
fixes (which I consider to be more "real world" true) until all Charts
have been corrected using GPS/DGPS readings.
The Major point...... NO one systems is perfect. To rely solely on one
system is to invite disaster.


otn

You have not sailed much then. Where I come from, water can be 2 feet
deep and there hasn't been land in sight for a long long time. Sail the
Caribbean, Maldives, South Pacific, or any of many other areas where
reef and rock is just waiting to bite you in your butt.

I also never said to try to dead recon anywhere. I said you sure as
hell better know how if you need to!

Navigation is using all means to know where you are at all times. I use
a gps and I double check my position with what ever is available, then
I check it on my chart to be sure everything agrees and I log it with
the current weather conditions and I do it every half hour when my
timer goes off. If you use one thing and trust it, how smart are you?

You want to turn some sort of table with your side handed comments but
you really should be open to a little learning. You're not the only
one you could kill. Arrogance is not praiseworthy. What have you got
against learning something or at least letting someone else learn it.

If you don't understand it, it doesn't make it worthless.