Re: Genoa and other stuff

djensen@mail.teleport.com
Tue, 18 May 99 18:38:06 +0000

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West Wight Potter Website at URL
http://www.lesbois.com/wwpotter/
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Interesting. Perhaps it was more of a perception issue than current, but we
could tack from port to starboard without a problem, but could not tack the
reverse no matter how we tried. (Paddle tacking excluded!) THe main difference
seemed to be that we were headed almost dead downstream on a starboard tack and
directly across the river on a port tack. Like I said, it was wierd. The
upshot seems to be that tacking with the genoa seemed to add more windage up
front thus making the boat less likely to come thru the eye of the wind before
losing way and stearage, the current somehow amplifiying this problem. In
general I do not have trouble tacking the genoa, this was just one data-point.

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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