Jim Donohue wrote:


Ohhh you use something besides GPS and DR and LORAN and RADAR?

G I'm assuming you just mentioned those 4 for brevity.

Perhaps you
might have a claim on a gyro compass...but other than that I doubt you use
anything different than I do. I would agree that you likely use them at a
higher skill level and more facilely than I...but that does not change the
fact that we rely on the same technology for the same purpose. Then again I
suspect I understood some of it better than you do. Can't tell that for
sure but with your closed mind I doubt you innovate well under pressure.

I don't doubt in the least that you may have a greater understanding of
some of the "engineering" involved with the electronic systems in
discussion. However, where their practical application is concerned.....
In that vein, I suspect you consider my mind closed because I disagree
with your approach and reasoning that goes with that approach.



You continue to confuse different issues. The eye as an instrument in
navigation is a useful one for piloting situations...particularly as a
continuous check. Its use in this way is however limited by the visibility
conditions. The eye also serves as an input device to the human but that is
a different use then navigation. Don' obfuscate the issue with the second
use.

G Then don't denigrate the use of the "eye" because on some days the
visibility may be less than perfect.


And you have made it clear you do not understand the well documented and
science based limitations of radar. This probably makes you a worse sailor
than most otn. Your view that radar always provides an accurate picture of
the physical world is a dangereous one likely to lead to bad outcomes. To
rely upon radar rather than a GPS for your primary positon is foolish under
most circumstances I can imagine. Ohh I am sure you can set up some weird
harbor situation where radar is effective and GPS is not otn...but that just
proves the old adage that there are exceptions to all rules. Now if a
positon difference exists between the radar and your chart plotter...you now
have doubt and have to use the brain to sort it out.

NO Jim. I fully understand the documented and science based limitations
of radar. More importantly, I also understand the operator/observer
limitations and plusses. I have never stated that radar ALWAYS provides
an accurate picture ... it can't for many obvious reasons.
However, in the hands of a competent operator/observer, radar becomes a
highly accurate tool of navigation and in many cases a better "primary"
tool for positions due to it's relatively quick update and "birds eye" view.
I don't need to set up some weird harbor condition to show this, G as
I frequently use radar as my primary and GPS as my secondary.


We are talking navigation otn..navigation. Navigation is not the only task
in boating.

I was keeping to the subject at hand.

snip I was going to comment on a few issues, but then I came to this next.


Oh? Interesting. I'm running a range (either manmade or one I've
determined, cause I can read a chart) and I pass abeam of a light house
and put a mark on my chart. Will GPS be more accurate? Faster?


Yes the GPS will be more accurate and faster. If the GPS does not agree
with the range/lighthouse you now have doubt and have to sort it. Get used
to it otn...in five or ten years that light is gone.

Interesting. Please explain how GPS will be faster and/or more accurate.
Which is most apt to show an error which may cause you problems?
As for the last sentence .... Jim, I chose a "lighthouse". I could have
said "buoy", but we both know why that wouldn't be good. I could also
have said a point of land, a charted building, etc..
Hopefully, those with seagoing experience who understand the value of
lighthouses even in this "GPS Centric" age will keep that house operating.



Oh, and where did I say that? You don't watch depth at your positon otn?
You are so secure in your visual/radar pilotage that depth is not an issue?
Yeah right. I did not say that the only use for a fathometer is checking
position...but it is a good one.

Sheesh, and you say I misstate and misread.
Jim, I said obviously you've never used the fathometer for "navigation".
I was referring to the practice of determining your position based on
soundings alone. It's one of those "innovations" you use, under pressure.


And so do I...well not quite...I don't generally fire up an antiquated RDF
and locate off the local radio stations. I could. But it is time consuming
and unlikely to provide much information except under unusual circumstances.

Hey, sometimes that's all you need.

I suppose under these circumstances you would assign a crew member to
operate the RDF and feed you cross checks but I do not have unlimited
resources on my bridge...such as it is.

G Using an RDF is like reading a Radar. I doubt most young Mates would
be too competent, so if it got to that point I'd probably leave them
behind the Radar, etc., while I did the RDF..... course, with all else
available, I must all ready be in deep doodoo if I'm having to revert to
that, but hey, sometimes that's all you need.


G I'd call that "teaching by amateurs, for amateurs".


I am sure you would...but you do that otn. Reach down into your mind and
see if you can explain what you would do instead otn.

I don't like your basic approach "start at the top and work backwards".
I still firmly believe in starting at the bottom and working up gives a
far better understanding of the issues involved.


Depends on whether you believe in the "half assed" approach .....
obviously you do.


And what is your "whole assed" approach otn?

See answer above.


Why I think your closed mind fits very well on the bridge otn...you know
what you know...you don't know why it is true or understand the
alternatives...but you know what you know.

Sometimes, your conclusions astound me. This is one of them.
The Captain and Mates on the Majesty screwed up in many ways. The
central screw-up was being "GPS Centric". They relied solely on the GPS
and it's high end plotter and auto pilot, when all around them were
tools which were showing that a problem existed, if they'd just used them.

otn

On Mon, 24 Jan 2005 19:10:28 GMT, otnmbrd
wrote:


Why I think your closed mind fits very well on the bridge otn...you know
what you know...you don't know why it is true or understand the
alternatives...but you know what you know.

Sometimes, your conclusions astound me. This is one of them.
The Captain and Mates on the Majesty screwed up in many ways. The
central screw-up was being "GPS Centric". They relied solely on the GPS
and it's high end plotter and auto pilot, when all around them were
tools which were showing that a problem existed, if they'd just used them.


Actually, the GPS was not in use. It was just that nobody thought to
check if it was for 600 nm. Reconnecting the antenna would have solved
the problem, as would have several of the other things nobody bothered
to check.

They were "integrated-bridge-system centric." A significant
difference.





Rodney Myrvaagnes J36 Gjo/a

"If any question why we died
Tell them, because our fathers lied." --Kipling

Rodney Myrvaagnes wrote:

Actually, the GPS was not in use. It was just that nobody thought to
check if it was for 600 nm. Reconnecting the antenna would have solved
the problem, as would have several of the other things nobody bothered
to check.

They were "integrated-bridge-system centric." A significant
difference.

It's a point, but let me explain why I'd put the main blame to "GPS
centric".
When they left Bermuda they had three systems available for Navigation.
GPS, Loran, Celestial. Since the GPS wasn't working, the integrated
system reverted to DR (and obviously did a damn fine job, considering)
and followed the prescribed track (here, I'm not sure of a doppler input).
Other than a cursory check of the Loran and, it would appear, no system
check of the GPS (no celestial was used) the "system" was allowed to
proceed.... i.e., the Loran positions were not all that far from the
assumed GPS.
Now, on the approach to the Nantucket-Boston Safety Fairway, things
should have changed. Your Loran is pretty good, You come on soundings,
You have Radar Targets, You can make allowances to use visual checks,
You know there are strong, contrary currents in the area, but none of
these tools were seriously used and none of the dangers were considered.
Why? Because the navigators were GPS centric, believing their Nav
Plotter was getting the correct information from the GPS and not using
other "systems" to confirm that this information was correct.
The fault here was not GPS nor the integrated system. The fault here was
navigators relying solely on one system to be correct all the time.
If you are going to be navigating, you want back-ups to your back-ups.
Sure, You can carry 20 hand helds and 4 cases of batteries, but what
happens when the Chit, negatively hits the fan and all you know is GPS?
What happens when the system fails and you are not aware of it and you
go merrily on your way, believing it's working?
No, they were GPS Centric. They believed everything was fine, when a
system check would have said otherwise. They didn't use back-ups/double
checks, they believed the GPS would always work so consequently the
integrated nav system must be correct and never needed checking on, for
whatever reason.

Basically what I'm saying is go back to the first basic error. The GPS
wasn't working, no one checked to see if it was... they were "centric"
in that they assumed it would be, when in truth, for any number of
reasons it may not be and the prudent navigator realizes this and
checks, especially in areas such as the Nantucket-Boston Safety Fairway.

otn

On Tue, 25 Jan 2005 01:59:45 GMT, otnmbrd
wrote:

When they left Bermuda they had three systems available for Navigation.
GPS, Loran, Celestial.

====================================

LORAN has always been worthless in Bermuda unless something has
changed in the last 10 years that I'm not aware of. Prior to GPS we
used to lose electronic navigation about 400 miles offshore.

Wayne.B wrote:
On Tue, 25 Jan 2005 01:59:45 GMT, otnmbrd
wrote:


When they left Bermuda they had three systems available for Navigation.
GPS, Loran, Celestial.


====================================

LORAN has always been worthless in Bermuda unless something has
changed in the last 10 years that I'm not aware of. Prior to GPS we
used to lose electronic navigation about 400 miles offshore.


Worthless in what way? Accuracy or reliable signal? I ask, because that
was not my experience.
Assuming you are correct and this applied to the ship also, would you
agree that as they approached the Nantucket-Boston Safety Fairway that
Loran became useful?
I ask because it does not appear that they were having a problem with
Loran reliability at sea, but also because it's use became more
important as they approached land, if, as I say, they were GPS Centric,
when others systems could have "saved the day".

otn

On Tue, 25 Jan 2005 03:21:21 GMT, otnmbrd
wrote:

Worthless in what way? Accuracy or reliable signal?

Reliable signal. My experience with LORAN in Bermuda is somewhat
dated and things may have improved, or you may have better equipment
on large ships than we did on sail boats in the late '80s. By the
early 90s everyone was using GPS so LORAN didn't get much attention
after that. My present boat has two very decent LORAN units aboard
and neither are connected, mostly for lack of antenna space. Don't
really miss them with 3 GPS units, 3 chart plotters, and two radars
available.

I ask, because that
was not my experience.
Assuming you are correct and this applied to the ship also, would you
agree that as they approached the Nantucket-Boston Safety Fairway that
Loran became useful?

LORAN should have been quite usable in that area in my experience.
The only time we had difficulty with coastal LORAN was during severe
thunderstorms. One of my units would also jump out of sync
occasionally but the error was so large as to be immediately obvious.

On Tue, 25 Jan 2005 03:21:21 GMT, otnmbrd
wrote:

Wayne.B wrote:
On Tue, 25 Jan 2005 01:59:45 GMT, otnmbrd
wrote:


When they left Bermuda they had three systems available for Navigation.
GPS, Loran, Celestial.


====================================

LORAN has always been worthless in Bermuda unless something has
changed in the last 10 years that I'm not aware of. Prior to GPS we
used to lose electronic navigation about 400 miles offshore.


Worthless in what way? Accuracy or reliable signal? I ask, because that
was not my experience.
Assuming you are correct and this applied to the ship also, would you
agree that as they approached the Nantucket-Boston Safety Fairway that
Loran became useful?
I ask because it does not appear that they were having a problem with
Loran reliability at sea, but also because it's use became more
important as they approached land, if, as I say, they were GPS Centric,
when others systems could have "saved the day".

otn
According to the report, the loran was behaving correctly near
Nantucket, where it mattered. Nobody believed it.



Rodney Myrvaagnes NYC J36 Gjo/a


"Accordions don't play 'Lady of Spain.' People play 'Lady of Spain."

Rodney Myrvaagnes wrote:


According to the report, the loran was behaving correctly near
Nantucket, where it mattered. Nobody believed it.



Rodney Myrvaagnes NYC J36 Gjo/a


G GPS Centric

otn

On Tue, 25 Jan 2005 01:59:45 GMT, otnmbrd
wrote:

Rodney Myrvaagnes wrote:

Actually, the GPS was not in use. It was just that nobody thought to
check if it was for 600 nm. Reconnecting the antenna would have solved
the problem, as would have several of the other things nobody bothered
to check.

They were "integrated-bridge-system centric." A significant
difference.

It's a point, but let me explain why I'd put the main blame to "GPS
centric".
When they left Bermuda they had three systems available for Navigation.
GPS, Loran, Celestial. Since the GPS wasn't working, the integrated
system reverted to DR (and obviously did a damn fine job, considering)
and followed the prescribed track (here, I'm not sure of a doppler input).
Other than a cursory check of the Loran and, it would appear, no system
check of the GPS (no celestial was used) the "system" was allowed to
proceed.... i.e., the Loran positions were not all that far from the
assumed GPS.
Now, on the approach to the Nantucket-Boston Safety Fairway, things
should have changed. Your Loran is pretty good, You come on soundings,
You have Radar Targets, You can make allowances to use visual checks,
You know there are strong, contrary currents in the area, but none of
these tools were seriously used and none of the dangers were considered.
Why? Because the navigators were GPS centric, believing their Nav
Plotter was getting the correct information from the GPS and not using
other "systems" to confirm that this information was correct.
The fault here was not GPS nor the integrated system. The fault here was
navigators relying solely on one system to be correct all the time.
If you are going to be navigating, you want back-ups to your back-ups.
Sure, You can carry 20 hand helds and 4 cases of batteries, but what
happens when the Chit, negatively hits the fan and all you know is GPS?
What happens when the system fails and you are not aware of it and you
go merrily on your way, believing it's working?
No, they were GPS Centric. They believed everything was fine, when a
system check would have said otherwise. They didn't use back-ups/double
checks, they believed the GPS would always work so consequently the
integrated nav system must be correct and never needed checking on, for
whatever reason.

Basically what I'm saying is go back to the first basic error. The GPS
wasn't working, no one checked to see if it was... they were "centric"
in that they assumed it would be, when in truth, for any number of
reasons it may not be and the prudent navigator realizes this and
checks, especially in areas such as the Nantucket-Boston Safety Fairway.

otn
We agree on what went on. I would still call it what I did. They
didn't ask the bridge system what input it was using.

Idiots anyway, for all their licenses.



Rodney Myrvaagnes NYC J36 Gjo/a


"Accordions don't play 'Lady of Spain.' People play 'Lady of Spain."

Rodney Myrvaagnes wrote:


We agree on what went on. I would still call it what I did. They
didn't ask the bridge system what input it was using.

Idiots anyway, for all their licenses.



Rodney Myrvaagnes NYC J36 Gjo/a

System checks .... an important pre-departure and daily check that is
becoming more involved.
At any rate, we can disagree on the basic "Centric" fault, the results
were the same.

otn