"Donal" wrote in message
...

"Jeff Morris" wrote in message
...
"Donal" wrote in message
One lash for asking a silly question.

Its not a "silly question," its a trick question, which can't be answered
with
one more piece of information. The key is that every sailor should know
the
Establishment (or Lunitidal Interval) for their home port, and others they
frequent. Do you know yours?


I'm not sure that there is only one piece of information missing!!


All I need to know is that when there is a full, or new, moon the HW will be
around 13:00.

Well, there are a few other details that aren't stated, like the presumption the
tides are semi-diurnal.

If you know the times of moonrise/moonset then the relationship between lunar
noon (the midpoint of rise and set) and high tide is relatively fixed. Thus,
the relationship you observe about the time of high tide and the state of the
moon can be used throughout the month.

I'm assuming you're talking about Portsmouth. If so, you should double check
your understanding of the tides. Full Moon last occurred on about 5 hours ago,
May 4 at 9:35 pm BST. High tide was at 12:06 am on May 5.

"Jeff Morris" wrote in message
news
"Donal" wrote in message
...
All I need to know is that when there is a full, or new, moon the HW
will be
around 13:00.

Well, there are a few other details that aren't stated, like the
presumption the
tides are semi-diurnal.

If you know the times of moonrise/moonset then the relationship between
lunar
noon (the midpoint of rise and set) and high tide is relatively fixed.
Thus,
the relationship you observe about the time of high tide and the state of
the
moon can be used throughout the month.

I'm assuming you're talking about Portsmouth. If so, you should double
check
your understanding of the tides. Full Moon last occurred on about 5 hours
ago,
May 4 at 9:35 pm BST. High tide was at 12:06 am on May 5.

Fair enough! I should have said that springs were at 13:00.



Regards


Donal
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