"Ted S." wrote in message
...
Thanks for the information but I don't think it is what I'm looking for.
I can find tide charts. What I am looking for is a value called the
Lunitidal Interval which is "the interval between the moon's transit of a
particular meridian and the next high tide at that meridian."

I need this value to program a watch so it is correct for the tides at a
location. I already have the longitude and GMT (time correction).

If there is a way to calculate this value from tide charts, that would be
useful information that I could use.

Thanks again.

Ted
Accepted Datums (W7) - National Tidal Datum Epoch (1983-2001)

Station -- Unique seven character identifier for the station
MHHW -- Mean Higher-High Water
MHW -- Mean High Water
DTL -- Mean of MHHW and MLLW
MTL -- Mean of MHW and MLW
MSL -- Mean Sea Level
MLW -- Mean Low Water
MLLW -- Mean Lower-Low Water
GT -- Difference between MHHW and MLLW
MN -- Difference between MHW and MLW
DHQ -- Difference between MHHW and MHW
DLQ -- Difference between MLW and MLLW
HWI -- Greenwich Mean High Water Interval in Hours
LWI -- Greenwich Mean Low Water Interval in Hours

Data are in Meters - referenced to station datum
8534770 VENTNOR CITY, FISHING PIER , NJ
Click HERE for further station information including New Epoch
products. ------------------------------------------------------------------
--------------
Station MHHW MHW DTL MTL MSL MLW MLLW
GT MN DHQ DLQ HWI LWI
8534770 2.918 2.790 2.213 2.175 2.185 1.560 1.507
1.411 1.230 0.128 0.053 12.29 6.09

High water lunitidal interval
The high water lunitidal interval (or high water interval) is the time
interval between the moon's transit and the next high water. The interval
may be taken from the local time of moon's transit to the local time of high
water, or it may be taken from the Greenwich time of the moon's transit to
the standard time of high water.

Mean high water interval
The mean high water interval is the mean value of all the high water
intervals throughout at least a lunation of 29 days.

Use the table below to set the moon/tide mode of your watch
Mean lunitidal intervals (mean high water intervals) have been calculated
using

Interval (hrs) = M2 phase (degrees) x M2 period (hrs) / 360 (degrees)

Hope this helps.

-swatcop