"Jeff Morris" wrote in message
...
Jim Donohue wrote:
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Ahh Bull otn...I use the same navigational procedures as you otn...and I
understand why the work something you do not. The eye is a most
important piece of navigation...unfortunately it does not work at all a
great percentage of the time. Radar is fine under some circumstances but
not very good under others. Only GPS works with accuracy all (for
practical purposes)the time. It is therefore the first of many tools
employed.

Anyone who has been on a boat knows that a GPS *DOES NOT* for all
practical purposes work all of the time. I've had a GPS fail several
times, I've seen charting inaccuracies a number of times. Similar things
have happened to almost every cruiser I know.

You lead an unlucky life. I have never seen a significant outage of the
GPS. I follow the tech literature on the subject. Aside from deliberate
military actions the outages are very few, far between, and limited in time
duration. As I said I have never seen one.

It is of course possible that you have a source of interference on your
boat. That does happen. It is one of the reasons that multiple GPSs are
sensible. Different devices have different weaknesses. I am sure there
are also some specific locations that have a multi-path problem. Again
though few and far between. GPS ain't perfect but it is very close. Done
with redundant instruments on the open sea it is, for all practical
purposes, perfect.

The present cruiser population is certainly and effectively completely
dependent on GPS for off shore navigation. At this point I don't think
there are many exceptions left. I have not come across a report of a
significant problem with that in a long time.

Charting inaccuracies are chart problems very close to completely. Without
gps they are hard to detect. The ones on the West coast of Mexico however
are detectible with a good LORAN.

None of these incidents were a major problem for me because I was using
other techniques and was able to recognize the situation and compensate.

The issue here is not which technique is the most accurate, or which
should be used to the exclusion of the other. Continuing to cast it in
these terms make you look like a jaxian fool.

One uses all reasonable methods available. The first and primary of these
is GPS. Your inablity to understand this simple statement is almost jaxian.

The issue is that you claimed it was foolish to teach someone basic
piloting, even when the person was eager to learn. This attitude marks
you as a complete fool, Jim. I hope I never meet one of your students on
the water.

No my argument was that basic navigation...not piloting...was better taught
with GPS as the primary technique. It was in response to an individual
teaching basic navigation with electronic aids removed. It is even possible
that the individual involved and I would end at the same end point. Just
different routings.
...




And you again utterly misstate my position. GPS is the first skill
taught...it should be the centerpiece of the navigation system. Then
others. Certainly even the dullest of students can learn to check a
chart position via eyeball or radar.

Are you daft, man? Are you claiming now that piloting need not be taught
because "even the dullest" can do it without training? And radar too?
Bizarre, considering you've confessed to have weak radar skills!

Listen carefully. Pilotage is important. One teaches navigation with the
GPS first. The first portion of that instruction is the use of charts. A
current student however should learn with the GPS positon centric techniques
rather than the LOP techniques of conventional DR. Yes eventually these get
taught also...but secondary to what is the real world.


Neither has the accuracy to verify the position and bnoth are compromised
under some conditions but both are good checks for at least gross error.
A fathometer provides a way to verify that the depth is where it should
be for the position. Disagreement calls for caution.

True enough, however those that learn GPS first usually don't develop
these skills. This is the crux of the issue.


I use a second GPS to protect against a failure and to help resolve
anomolies.

I would not teach RDF or some of the more exotic piloting techniques. I
would not teach time delay loran though I would point out that a working
LORAN also provides a gross check on the GPS.

I would not teach VOR/DME...though I have used VOR in navigating a boat.

I would teach limited celestial for a student with the right mission.


TD's, RDF and VOR are not the issue. Bringing them into the discussion
shows you don't get it.


Now exactly what is it that you don't agree with and why otn?

You asserted that learning LOP's and DR was "utter nonsense." I think no
one should be trusted with a GPS until the learn these basics.

Uhhh where did it state that learning LOPs and DR was "utter nonsense"? I
think I made such a comment about teaching a student navigation with such
techniques emphasized to the exclusion of electronic navigation. Still do.

You correctly point out that it will be difficult to teach DR/LOP after one
learns electronic navigation. That is because it is difficult to convince
the student that sufficient value exists in such techniques. You deal with
this value problem by teaching DR/LOP first. I claim simple that this in
no way prevents the knowledge of DR/LOP going away real fast. I think we
need to develop that set of DR/LOP skills that will actually stick after
electronic navigation is learned. If we can't develop such a set and
convince the newby of value then the outcome is the same.

I stress the electronic navigation first because I think it more important
they do that well than that they master an initial set of techniques they
will abandon upon learning the electronic version. First good at the
primary system then good at the secondaries.

I introduce VOR/DME and RDF merely to demonstrate that we really don't
propose to teach all available navigation techniques...only those that we
believe useful and reasonable.

I, on the other hand, do not agree with relying solely on one SYSTEM!!
(The Royal Majesty is a prime example of why)My experience/opinion is,
you use ALL MEANS AVAILABLE to check and double check your position.
The fact that those older systems may have drawbacks, may not be as easy,
may not always be as accurate, may not always be available, is immaterial
.... they have to save your butt only once, to make them well worth the
learning.


The Royal Majesty had at least five systems on which it was relying. It
had
GPS, Loran, Depthsounder, radar and eyeball. Its procedures required
their use. The chief officer in fact lied about crucial visual
sightings. You would have fit right in otn all the right system, an easy
call but no nothing navigators who screwed it up. The message of the
grounding was that given a sufficient level of incompetence you can screw
up the simplest of tasks. It also demonstrated the level of utter
incompetence available among the "cream" of professional navigators.

The NTSB study blamed several "probable causes:" over reliance on GPS, and
lack of training of the officers, and the failure to recognize the problem
from other cues. This is a perfect example of problem with your approach.
Claiming that your strategy works, but in this case they were incompetent
is foolish.

http://www.ntsb.gov/publictn/1997/MAR9701.pdf

I am reasonably familiar with the report. Find for me any mention of over
reliance on GPS. It does find fault with over reliance on the automatic
features of integrated bridge systems. It also discusses flaws in the
design of such systems. I agree that total reliance on a single GPS is not
wise. I generally run three...and two are active in the process to try to
avoid the entry errors that I believe are the worst problems with GPS
navigation. When the europeans get their system operative or the Russians
complete theirs I will almost certainly run one GPS off another system. I
will also use other inputs like depthsounders and radar to help prevent
errors.

Jim