DSK wrote:
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!

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


Well, all it's doing is solving the relative bearing drift for you. If a
person doesn't know how to do this for themselves, then they can't
navigate. Period. It's one of the basic skills.

Of course, under most circumstances you can let the machine do it for
you. But I'm of the old school that says it's better to know how, yourself.

Another poster here said, a long time ago: "When people complain that
learning to navigate the old-fashioned way is difficult, slow, & boring,
you can always answer that crashing your boat into the rocks is easy,
fast, and exciting!" It's the best answer I've heard.

Fresh Breezes- Doug King

When you take a bearing using RDF of a coast station that you want to
get to you don't steer the bearing on the RDF. That bearing is called a
"curve of constant bearing" and is only part of the solution. The
curve of constant bearing can be either north or south of the actual
bearing to the station unless both the ship and the station are either
on the equator or on the same longitude. What you have to apply to any
other bearing to get the Rhumb line is half convergency. That will give
you the course to steer.

The same problem applies when using RDF bearings to plot a fix. Those
are not straight lines from the radio station but curves of constant
bearing and the resolution of the fix becomes a sperical trig problem
unless you use the half convergency tables to correct those bearings.
Of course the closer you are to the radio station the less the correction.

GPS is better, way better.

Gaz