Jim Donohue wrote:
"Jeff Morris" wrote in message
...
Jim Donohue wrote:
Sorry Roger...but the guy is not teaching all methods...he is teaching
some version of DR and coastal. He is deliberately not teaching GPS and
Loran. So he is busily training a 1975 sailor.
Sailors in 1975 were much better navigators than today.
OK...There is a bold and clear statement. Lets see your reference. Let's
see a study that indicates the ability of sailors to navigate has gotten
worse than it was in 1975.
I cite myself as an expert witness. With a Texaco chart, an AM radio
and a spinning neon bulb the navigator of 30 years ago had much better
basic skills than today.
You have apparently sailed at least a few times
Jeff...why would you make such a singularly stupid assertion.
Are you actually claiming that the average newbie boat owner knows even
the basics of navigation nowadays? Yes, with a GPS everyone is an
"expert navigator." Take it away and half the boaters need Seatow to
get back home.
I would strongly hold for teaching all useful methods...but the important
ones first. In fact the first skill is the ability to read and interpret
a chart...which is I think the skill that is often missing in beginning
sailors. Then GPS. I would certainly teach DR and coastal...but as a
secondary to GPS.
That makes as much sense as teaching 4th graders how to use a calculator
assuming they will figure out long division later. If someone was
insisting on receiving no more than an hour or so of instruction before
heading out, I might be tempted to show them a GPS, but if someone wants
to learn the basic methods they should learn them first.
Further, to fully appreciate a chart you must learn the basics of
piloting. You can explain variation and bearings, but they has no meaning
to beginners until the plot LOPs.
Heading and bearing are perfectly reasonable and understandable terms even
for the beginner. They are perfectly explainable in the context of a GPS
location.
You're confusing "explaining" with "learning." Anyone can nod their
head while listening to a 5 minute explanation. Knowing how to do
something requires practice.
One need not plot LOPs when one knows the position. It would be
better to be positon centric.
In other words, its impossible to determine a bearing to point B from
point A unless you're actually at point and can ask the GPS? And you're
saying its easier to punch in the Lat/Lon of point B than to look at a
chart?
What we use to do was deal with the fact that
the fix was to a line and not a position. That is not a desirable
outcome...merely the result of technical limitations. Crossing to lines is
simply a way to get to the information that is directly avalable from the
GPS. Why would you want to determine position by crossing to lines when it
is available directly from an instrument?
So your point is that as long as you have a GPS other forms of
navigation are unnecessary and therefore shouldn't be taught? And when
the GPS fails? Right - Call Seatow!
Variation is simply compensation for instrument error that no longer
exists. Why would you feature it in your early instruction?
Without taking it into account a heading is off by 16 degrees in Boston.
More than enough to get you in trouble when following a compass
course. Unless you think compass skills are not important, it must be
taught. You can't dismiss it as "just instrument error" since it varies
with the location.
As we cannot
yet get rid of the magnetic compass it is still neccessary to explain why
there are two heading systems. It should be handled for what it is...an
instrument error to be compensated when using the compass for heading.
What's your point? If the compass is important Variation must be
taught. Its part of basic piloting skills. You seem to be agreeing
with me.
How far do you plan to go on "teach all methods"? I can interpret and
use an old Loran with the delay numbers...but I would not teach it.
Celestial is the obvious issue. Would you teach celestial today to a
prospective cruiser? What level of celestial? The full set of star/moon
techniques? How about RDF?
These are silly comparisons. Basic DR and piloting techniques are used
all the time even in our GPS oriented world. Loran and celestial are not.
However, a few of the basics should be taught - I'm surprised at how many
people can't instantly find Polaris, or know the approximate bearing of
the rising or setting Sun or Moon.
Oh? So as long as it is on your hobby list it is basic and required?
They are on my "hobby list" but since a novice is would not likely use
them, they need not be taught. The basic piloting skills can (and
should) be used every time you leave the dock.
Otherwise it is not? The discussion is to use all available methods.
Actually, I only took exception to your comments about basic DR and
piloting skills. "All available" is pretty far reaching, but the basic
skill can be used all the time.
Why would you not want Loran?
When I've cruised on boats that have a Loran I've turned it on to
reminds myself how they work.
A lot more accurate than DR or any piloting
techniques I know of.
Accuracy is not the point. There's is no doubt that GPS is usually much
more accurate than any other method. This reminds me of the time I
watched a trawler run aground on the ICW. He started screaming on the
radio that he was "right on the magenta line!" I was following my depth
sounder and was in 20 feet of water. Who was more accurate in this case?
And you calculate drift angles all the time? What
for?
Calculate precisely? No. But I do manually adjust my bearing for a
crosscurrent. Are you saying you don't know whether its flood or ebb
without using the GPS???
You find it intellectually stimulating to calculate it rather than
have the GPS read it to you?
I call it good seamanship. If you're crossing a harbor with strong
currents its nice to be able to predict the affects in advance. Waiting
for the GPS to tell you you're screwed is just plain stupid. And this
is the essential fallacy of your argument.
My point is actually simple. The proper
primary instrument is the GPS which tells you where you are and which
direction you are heading. You guys are trying to assert it should be the
magnetic compass.
WRONG! The primary instrument should be your brain!
You simply are backing a dead horse. It is over. Get
over it. Teach reality not your hobby views.
Reality is that GPS fails. The power line corrodes. The batteries die.
Lightning zaps it. The are gaps in the charting. Features are
mis-plotted. Handhelds get dropped. Antennas get loose.
Further, unless you have an expensive system, its tedious to setup a
complex route, and hard to make adjustments on the fly. If you are
practiced in piloting you can get an approximate heading from a chart in
a few seconds - much faster than you can in a small GPS.
For planning purposes basic skills allow you to quickly determine
headings and ETA's. Knowing whether a day trip will be a reach or a
beat - this is much easier to determine with a chart than a gps.
And how useful is a GPS while weaving through a twisty channel? Often
is is more of a distraction than an aid.
As an aside virtually all Pacific cruisers as of a year or so ago had a
sextant on board...but virtually none had shot a positon in the last
year.
Is there a point here? I'll bet that the majority of them knew the basics
of DR and piloting. Or are you claiming they don't bother because they
have faith in their GPS?
The point, which was listed as an aside...is that the real cruiser
population uses GPS effectively exclusively and their ability to revert to
celestial is probably not there.
Celestial is a complete red herring. We're talking about novice
navigators, not passage makers. You can make a good case that GPS has
made Celestial obsolete. You can't make the same case that piloting
skills are obsolete.
DR is a silly argument in this
context...
DR skills are used all the time. While plotting DR's on a chart may be
a vanishing art, every time you make a guesstimate of how far you've
gone, you're practicing DR.
it is simply a way to determine how lost you are...It is probably
less effective than following airplanes in most of the world.
Following airplanes? Again you're confusing offshore navigation with
piloting.
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