Derek Jensen
p-15 #694 "El Nino"
Portland, OR
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> West Wight Potter Website at URL
> http://www.lesbois.com/wwpotter/
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> Derek wrote:
>
> >I've also noticed that the sail sometimes makes it hard to tack in certain
> >weird
> >conditions, but I also attribute that to the fact that the prevailing
> >condition on the >Columbia often finds one traveling with the current and
> >thus reducing the water flow over >the rudder.
>
> I believe the speed you make through the water (and thus your rudder
> effectiveness) is essentially independent of the current. The current only
> affects your speed and direction over the bottom.
>
> An exception might be a momentary change in current, where the boat's
> inertia may cause a momentary delay in the boat's response to the change in
> velocity or direction.
>
> It's comparable to an airplane in flight, where the airspeed is essentially
> unaffected by wind velocity or direction. Again, the exception is an abrupt
> change in velocity or direction of the wind, as in a "wind shear" situation.
>
> Harry Gordon
> P14 #234, Manatee
> Mountain View, CA
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