| It's dependant on many factors to be honest.
Another noticeable influence is the weather! Say you are diving a site that is near a major river mouth, like the Fal, or the Helford in Cornwall, and the previous week has been appaling - constant rain. This rain will end up in the river and all this crap will be present when you do your dive in the form of mushy Viz!
You tend to get Plankton blooms later in the year which affect viz also.
In all fairness I tend to find that if you stay away from Springs and Neaps you have a better chance of better viz! |