in the world of super computers, that used to be called "double-precision
[meaning calculated to 16 decimal places] guesswork".


precision math does not make guesses more accurate.

correction: that is an *estimated* 089, and an *estimated* 11.14
knots.

It's accurate with respect to the mathmatical principle being employed.


And even that *estimation* is off by whatever leeway you get from the
wind, whatever variation you get as to speed and direction, plus
whatever variation you get between the direction the boat points and
which way it heads under pefect conditions, plus whatever variation
you get in pointing and speed due to waves and wave direction and
speed and height.

I am perfectly aware that DR is not precise when applied in the field.
However, the principle has to be applied precisely when working out the
vectors - to do otherwise would be to introduce another layer of potential
error. The point is to produce the best estimate you can on the basis of the
available information. To take a bunch of estimates, and then screw up the
numbers would be stupid.


--
Wally
www.artbywally.com
www.wally.myby.co.uk