I apologize, some of the graphs have very thick lines, i will correct that in future posts. Just as a side note i wanted to add this last graph of swell period plotted against swell height. This data was taken by the 12 meter node.

This graph shows some correlation between swell height and visibility. However it does not show a relationship between swell period and visibility. All three visibility categories cover a wide range of swell periods. The three categories begin to separate from one another when we look at swell height. This is the strongest relationship I've seen yet.