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Jeff Morris
 
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Default Question: Judging High Tide by the Moon

Walt -
While the "theory" might imply high tide at lunar noon, it doesn't work out that
way in practice.

For instance, in the Gulf of Maine high tide precedes lunar noon by less than an
hour. But then you go down to Block I and the tide is almost 4 hours before
noon. Cape May is also almost 4 hours early. This continues all the way down
the down the coast to the Keys. In fact, there isn't a place on the East Coast
between Cape Cod and Key West where high tide is within two hours of lunar noon.

Rather than randomly sampling tides, try looking at the tables I posted:
http://www.sv-loki.com/NETides.jpg
http://www.sv-loki.com/SETides.jpg





"Walt" wrote in message
...
N1EE wrote:

1 pt to you Wally.

High Tide will be somewhat close to the
mid point between moonrise and moonset.


In theory.

I have not researched many lcoations but I'd
estimate +/- an hour for more locations.


You need to do some more research. Use the following two resources to
compare moonrise/set times and tides for various locations:

http://www2.shore.net/~mcmorran/tide/tideform.html
http://aa.usno.navy.mil/data/docs/RS_OneYear.html
(be sure to correct for daylight savings time)

For instance, try comparing Virginia Beach, VA and Solomon's Island, MD
. Moonrise/set times are within a couple of minutes of each other, but
the tides are six hours out of synch.

Why? Well, obviously it takes some time for the large bulge of water
that is the tide to make its way up the Chesapeake Bay. Since water
doesn't move instantly, moonrise is essentially useless for predicting
tides on large bays.


--
//-Walt
//
// Sigs suck. Oh, the irony.