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Subject: Re: Wind & Current Navigation
From: Fred Hebard (Fred@XXX.XXX)
Date: Wed Apr 16 2003 - 23:26:26 EDT
Dan,
It's always nice to see problems posed on which one can ruminate.
We have a full moon tonight, which will increase tides. I believe the
tides also are increased by being near the equinox. So you may have
experienced much more tide than you usually encounter, although so soon
after low tide is puzzling.
The wind pushing you sideways is resisted by the keel(s) of the boat
quite a bit, whereas nothing resists the current, to a first
approximation. Also, you boat is not a perfect sail, as Peter Fogg
pointed out. Perhaps one of the engineers lurking near will enlighten
us on the efficiency of various types of sails.
When you are first getting underway, you have not had an opportunity to
evaluate the effect of the various forces pushing on your boat, so it
is more difficult to compensate. I can nervously envision that sinking
feeling as you were set in towards that pier with very little you could
do to get yourelf away.
Perhaps throwing a bit of chaff into the water in the future would be
enlightening, or looking at the water swirl around an anchor chain or
some such. The orientation of free-swinging boats at anchor relative
to wind direction might also be helpful.
Fred
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