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I don't think theory, except at the crudest level, will help practice
in this case. Your boat has a certain exposure to current, which may or
may not be the same at the surface as at the bottom of your keel. It
also has a windage exposure. The wind makes no difference in a calm,
but if it gusts hard enough it can become comparable to the current for
a moment.

So, current (if any) always matters, wind sometimes matters, and how
much depends on the boat. The current can be predicted from tide tables
after you have been there through a couple of cycles.

On Tue, 22 Apr 2003 08:56:00 -0700, Dan Allen wrote:

>On Monday, April 21, 2003, at 02:36 PM, Charles Tait wrote:
>
>> I severely doubt that any equation will fix this better than judgement.
>
>I know that the equations that govern marina navigation are very
>complex with currents and winds added, and that there may be no current
>good real-time calculation mechanism to make use of them.
>
>But I am looking for us to develop a more rigorous theory of what is
>happening so that we can learn from it and make some progress on
>understanding the physics of winds and currents so we can have some
>first principles to work from while at the helm.  I am therefore
>looking for the theory that will help practice.
>
>Dan



Rodney Myrvaagnes                                               J36 Gjo/a


"That idiot Leibniz, who wants to teach me about the infinitesimally small! 
Has he therefore forgotten that I am the wife of Frederick I? How can he 
imagine that I am unacquainted with my own husband?"

   

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