Larry wrote:
....

RDF is great as long as there is NO DRIFT, water current or wind drift.

If you don't learn to take that into account and just follow the RDF to the
station, you end up in this big spiral to the target, the long way around!


The same will happen with a GPS, unless you know how to use cross
track error. And its certainly better than simply following a compass
bearing.

Anyone capable of using RDF would also know how to use a compass, and
understand the meaning of the changing bearing. Today's GPS user
doesn't necessarily have these skills.

GPS, of course, doesn't suffer these 1930's problems.

1930's??? Most boaters couldn't afford Loran until the late 1980's.
And small, waterproof GPS only became available until about 10 years
ago. You sound like a n00b that took his "safe boating class" from
the jetski salesman last weekend.

Jeff wrote in :

The same will happen with a GPS, unless you know how to use cross
track error. And its certainly better than simply following a compass
bearing.



It will? How's that? My GPS has a few chart plotters connected to it.
They all have at least one, even without the chart plug. You know where
the waypoint is. It draws a line you follow, even if you're steering it by
hand.

How do you spiral in with this? You might be looking at the wrong display!

Larry wrote:
Jeff wrote in :


The same will happen with a GPS, unless you know how to use cross
track error. And its certainly better than simply following a compass
bearing.




It will? How's that? My GPS has a few chart plotters connected to it.
They all have at least one, even without the chart plug. You know where
the waypoint is. It draws a line you follow, even if you're steering it by
hand.

How do you spiral in with this? You might be looking at the wrong display!


Ah! So you're claiming that a GPS isn't really a GPS unless it has a
chartplotter, or two. Sorry, I didn't understand. And you know
you're being set because that little picture of a boat keeps drifting
off to one side. This is completely different from using RDF and
compass, where the compass bearing will keep shifting to one side.

On Thu, 09 Mar 2006 22:33:00 -0500, Jeff wrote:

Ah! So you're claiming that a GPS isn't really a GPS unless it has a
chartplotter, or two.

Even the simplest handheld will have a cross track error function
these days. Anyone who doesn't know what it is, or how to use it
really does not belong in a situation where navigation is required.

Wayne.B wrote:
On Thu, 09 Mar 2006 22:33:00 -0500, Jeff wrote:


Ah! So you're claiming that a GPS isn't really a GPS unless it has a
chartplotter, or two.


Even the simplest handheld will have a cross track error function
these days. Anyone who doesn't know what it is, or how to use it
really does not belong in a situation where navigation is required.

Yes, of course. And now for the third time I'll point out that
noticing the compass bearing of an RDF target change is no more
complex than watching the x-track change.

The ability to connect a GPS to an Autopilot and track a straight line
across a current is real spiffy. Being able to do it manually by
understanding what's going on around you is even better.

On Fri, 10 Mar 2006 08:19:30 -0500, Jeff wrote:

Yes, of course. And now for the third time I'll point out that
noticing the compass bearing of an RDF target change is no more
complex than watching the x-track change.

I agree but if you are starting to drift off your track line, you will
usually pick it up on cross track error well before you see a bearing
change of even one degree.

Wayne.B wrote:
On Fri, 10 Mar 2006 08:19:30 -0500, Jeff wrote:


Yes, of course. And now for the third time I'll point out that
noticing the compass bearing of an RDF target change is no more
complex than watching the x-track change.


I agree but if you are starting to drift off your track line, you will
usually pick it up on cross track error well before you see a bearing
change of even one degree.

Of course. I certainly wouldn't argue that RDF and Compass is more
accurate than GPS with x-track. My point is simply that anyone who
would unknowingly "spiral in" on an RDF target probably couldn't be
trusted to understand a GPS either.

If all you do is blindly minimize x-track you might not appreciate the
nature of the current, and how it's affecting other boats.

Actually, my recollection of using RDF is that when we approached a
harbor in limited visibility we made sure that the compass bearing was
shifting in the proper direction, to ensure we were on the proper side
of the transmitter.

Jeff wrote in :

Ah! So you're claiming that a GPS isn't really a GPS unless it has a
chartplotter, or two. Sorry, I didn't understand. And you know
you're being set because that little picture of a boat keeps drifting
off to one side. This is completely different from using RDF and
compass, where the compass bearing will keep shifting to one side.



Any GPS that has a DISPLAY is, by definition, a chart plotter. I don't
know of a single, cheap, even handheld GPS that doesn't have a plotter I
can put a waypoint into. There's none on the Raymarine Raystar 120, as
it's a feeder GPS for the Seatalk network, which has a display, which is a
chartplotter.....

NO RDF has any kind of a plotter I ever saw. It points to the station on
the null, duhh..

Why are we having this stupid troll? RDF is useless, now, a waste of
space. Use it to weight down the trash when you dump it overboard.

No, I don't have an astrolabe aboard, either!

On Fri, 10 Mar 2006 22:56:07 -0500, Larry wrote:

No, I don't have an astrolabe aboard, either!

Then how are you going to sail your latitude lines back to Spain?

Larry wrote:
Jeff wrote in :


Ah! So you're claiming that a GPS isn't really a GPS unless it has a
chartplotter, or two. Sorry, I didn't understand. And you know
you're being set because that little picture of a boat keeps drifting
off to one side. This is completely different from using RDF and
compass, where the compass bearing will keep shifting to one side.




Any GPS that has a DISPLAY is, by definition, a chart plotter. I don't
know of a single, cheap, even handheld GPS that doesn't have a plotter I
can put a waypoint into. There's none on the Raymarine Raystar 120, as
it's a feeder GPS for the Seatalk network, which has a display, which is a
chartplotter.....

This is fairly true today, though it wasn't even a few years ago. Not
everyone updates all of their electronics every year. And a two inch
screen is not always that easy to read, so my comment about
understanding x-track still stands. "Spirally in" can happen even
with GPS; in fact that could be how the boat ended up on the Miami jetty.


NO RDF has any kind of a plotter I ever saw. It points to the station on
the null, duhh..

No RDF (certainly not the RayJeff genre) was intended to be an
all-in-one solution like the modern GPS. In fact, none of the
traditional techniques could be used in isolation; they all required
an understanding of multiple methods. RDF only gives an LOP, no one
would simply "home in" on beacon, especially if there's a cross current.

No one would claim to be a competent navigator if all the knew was the
RDF. Nowadays, anyone how has a jetski with a gps claims to be a
"navigator."


Why are we having this stupid troll? RDF is useless, now, a waste of
space. Use it to weight down the trash when you dump it overboard.

I never claimed we should return to the RDF. All I did was point out
the error in your understanding of traditional navigation. Your
"spiral in" comment marks you as a n00b.

Ironically, your lame attempt to trash traditional navigation has
shown the great weakness of GPS: if you were alone at the helm and a
loose wire shut down your gps, you probably wouldn't be able to follow
a compass course!

No, I don't have an astrolabe aboard, either!
What good would that do you? You've probably forgotten how to use a
compass by now!