rice
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Reged: 07/02/02
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Loc: CA
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So I received a new Casio digital watch for Christmas. And, to set the tide, one needs to enter the longitude, difference from GMT, and the lunitidal interval.
The manual gives the lunitidal interval for various cities, LA being the closest to me. It gives the lunitidal interval for LA as 9:20.
I know that Morro Bay tides happen 55 minutes after those of LA. Do I just add the :55 to the 9:20 and go with 10:15?
It seems semi-accurate with this setting.
Any advice? 
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Anonymous
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rice
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Reged: 07/02/02
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Thanks. Yeah, I looked at that site.
So, it says that the interval can be found with,
Local Interval = GI - (0.069 * L)
I have L, obviously, but is the GI the High water interval or the low water interval?
It says, "To calculate the High Tide Local Interval, use the Greenwich Mean High Water Interval in Hours from the Accepted Datums page. To calculate the Low Tide Local Interval, use the Greenwich Mean Low Water Interval in Hours." But it doesn't ask for 'high' or 'low'.
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Anonymous
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rice
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Reged: 07/02/02
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Loc: CA
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It's actually one of the one's you suggested way back.
Sea Pathfinder
It seems like a great watch.
I'm trying to use the San Simeon tide info off of that page; it's the closest to me.
Thanks; I'll have to play around with it when I get home.
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centrlcoastkook
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Reged: 07/02/02
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If this is for real...then I hope Surfdad is laughing his ass off right now 
Karma is a bitch Rice!
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The bosom of California yields her angels. It's the last purity this geography can claim -nep
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rice
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Loc: CA
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Anonymous
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rice
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Loc: CA
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Thanks. Yes, I already contacted Casio and I have the manual at home; not much help.
Hey, I thought you said this was "easy"!
And yes, I ordered it from that same site; they have that watch for around half the price of others; what's up with that?
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rice
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Quote:
It is easy if you are in one of the cities.
It's real easy if you're in one of the cities; they give you the damn city lunitidal interval in the manual.
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Anonymous
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rice
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Reged: 07/02/02
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AAAAARRRRGGGGGGGHHHHHHHHHH!!
This is the response from Casio:
You may find the following Web page to be helpful for finding the lunitidal
interval:
http://co-ops.nos.noaa.gov/faq2.html#22
The formula you mentioned is found there. Use the Greenwich Mean High Water
Interval.
Alternatively, you can calculate the lunitidal interval by going to:
http://aa.usno.navy.mil/data/docs/RS_OneYear.html
First, you need to calculate the moon up. To do this, find the moonrise and
moonset for your location for a specific day. Halfway between these times would
be the moon up.
Next, find the tide times for your location for that day. These are usually in
most newspapers for cities that have a coastline, a local marina, or from the
following site:
http://www.saltwatertides.com/pickpred.html
The lunitidal interval is the difference from moon up until the first high tide
after moon up.
Simple right? Well, unless I'm doing something really stupid, which very well may be the case, the interval changes a little for any given day that I compute it (using the second method that Casio suggests). So, that doesn't really work.
So, going back to the first method, using the Grenwich Mean High Water Interval, I come up with 10:14 as the LI. Problem is, this does not seem to jive with the actual tides (it seems to show the tides earlier than they actually are).
Advice? Anyone?
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Anonymous
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Who's Your Daddy
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Reged: 01/10/02
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Quote:
Advice? Anyone?
surfdad seems to be the one to ask about tides, no?
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This space available for rent
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rice
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Loc: CA
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Yes, I'm using -8 GMT. I'm using the exact moon times.
Try it; tell me what YOU get.
Thanks.
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Anonymous
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rice
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Quote:
physical eyeballing of the tideline?
No, no, no.
Using the numbers.
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Anonymous
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rice
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I used the SaltWater numbers, which were the same as the Morro Bay Surfline numbers.
I'll monitor it this weekend and check the numbers/times on the highs and lows and let you know if it seems to be copacetic.
Thanks for the help.
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