jlrogers±³© wrote:
"Shaun Van Poecke" wrote in message
...
Here's one for those of you out there without onboard
instruments/knotmeter/gps....

Is there any reasonably accurate (say, within a know or so) way of judging
the current, when you are under way, and there are no fixed objects within
sight?

Yes, Shaun, there is. For your edification, I refer you to, "We, the
Navigators The Ancient Art of Landfinding in the Pacific," by David Lewis.
Specifically chapters 5, "Keeping course by Sun, Swills, and Wind," chapter
6, "Dead Reckoning," which directly addresses your question, and chapter 7,
"Orientation Concepts in Dead Reckoning."

http://books.google.com/books?vid=IS...H54BfXwOv1l5Zs

Ah! One of my favorites books! Thanks for the mention, I think it
may be time to read it again!

However, I don't think it supports your position. For instance, in
the chapter on Dead Reckoning, it begins the section on Current Set
with "This presents a difficult and intractable problem of which the
Pacific Island navigators were only too well aware ..." It goes on to
describe how they memorized all of the currents, and then took careful
back bearings on departure to determine how the currents were
deviating from the expected norm.

The traditional navigators did make use of a variety of signs, such as
the steepness of waves (as I mentioned in another post) but I doubt
the casual Western observer could reliably use these sign to measure
to within a knot.