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fishnchips
November 29th, 2004, 04:22 AM
I understand that fishermen use the moon to predict the availability of fishes. While the full moon and new moon affect the tides, does anyone has info on the correlation between moon and visibility, and correcation between moon and wave?

It seems that the week with full moon always has low vis. Any info would be greatly appreciated. Thanks.

roturner
November 29th, 2004, 04:57 AM
You might want to look at some websites about the tides. Here is one I know of:

http://www.getij.nl/engels/

There is a relationship between the tides and the phases of the moon. At around the full moon (or a day or two later depending on where you live) you get the largest tides of the month. At around the quater moon you get the lowest tides of the month. I suppose if your tidal flow moves silt off the bottom then it will have more of an effect on vizibility at spring tide and less at neaps.

R..

Charlie99
November 29th, 2004, 01:43 PM
There is a relationship between the tides and the phases of the moon. At around the full moon (or a day or two later depending on where you live) you get the largest tides of the month. At around the new moon you get the lowest tides of the month. A more accurate description for most places in the world would be that you have the highest tidal range (difference between low and high water) around BOTH the new moon and the full moon. The smallest tidal ranges are around the quarter moons.

roturner
November 29th, 2004, 02:34 PM
oops

my bad. You're right. Spring tides happen at full and new moons...

R..

Paul Evans
November 29th, 2004, 05:10 PM
I think wind direction has more effect on vis than moon phase :06: , onshore or offshore winds effect the vis in the Channel. the difference is quite alarming :11:

Hank49
November 29th, 2004, 05:25 PM
I think wind direction has more effect on vis than moon phase :06: , onshore or offshore winds effect the vis in the Channel. the difference is quite alarming :11:

I think the location and conditions of the dive site are factors as to whether tides or wind will affect visibility. Shallow areas with silty or muddy bottoms and more than 3 feet difference between high and low will likely have bad vis during peak tidal movement or high surf conditions. On the other hand, deep sea reef areas are unpredictable, There is no silt to be stirred but it seems that some days a plankton bloom of some type moves through and vis is not so good. Two weeks later with the same conditions, you can get 100 foot vis.

roturner
November 29th, 2004, 06:51 PM
I think wind direction has more effect on vis than moon phase :06: , onshore or offshore winds effect the vis in the Channel. the difference is quite alarming :11:


Well, what you're saying is true.... certainly wind and rainfall etc. can have as much or more impact on visibility than the tides; however, I think in response to the question (observation) that visibility can be affected by the phases of the moon (ie the tides) the answer must be yes. Depending on the location this will certainly be noticable.

R..

Wally1716
November 29th, 2004, 07:41 PM
...does anyone has info on the correlation between moon and
visibility, and correcation between moon and wave?
.

The moon affects and determines the tides...and the tidal currents, incoming or
outgoing, either bring clean deep water near shore or take the river and coastal
garbage out to sea. The viz is then affected by either incoming or outgoing tides.
Effect on waves is minimal. Pressure and wind are the main contributors to waves.
Current strength is affected by tidal change therefore by the moon.
.
Simple explanations on moon effects on tides, currents, and viz are posted in our
web site with address below. Scroll down to the three short articles explaining
these.

Please let me know if it is of any help.

Walter
November 30th, 2004, 10:20 AM
Visibility is mainly affected by how much gunk is suspended in the water. Lots of things determine that - bottom composition, currents, wind, rain, etc. You cannot expect to guess the viz unless you actually go look.

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