After being here several years, I've tried to notice trends in the sea life and water conditions. As has already been mentioned, it's hit or miss. There are a number of contributing factors. As has already been mentioned as well is water temp and wind direction. I don't quite understand yet what causes the June Grass(the alge type stuff in the water you mentioned). Obviously, from the name, you'd expect it around June. But, it seems to depend on how quickly the water warms up. Also, june grass is typically only found in much quantity right along the shore. You can go out to the second sand bar and on the other side of that you won't see hardly any unless you have an off-shore breeze come through. What's confusing about the June Grass is it seems that water temperatures warming more quickly causes more and causes it to stay longer. But, when it clears up the water is still very warm and generally has not started to cool down yet at all. If you keep tabs on the water temperature(which I haven't checked each year when I see it show up but I'll check this year), you will probably notice trends such as if the water is x degrees by x time, the June Grass will show within a certain time period. I believe, but just from a few years observation, that the earlier it shows, the longer it stays. We moved here Sept 2, 2001. The water was crystal clear with water temp in the mid 80s for quite a while after we arrived here. That year there were also hundreds and hundreds of Manta Rays cruising along the shore going East to West seemed like for about a month and there were tons of blue crabs that year. I expected the same the next year but June Grass was really bad in 2002 and although the Manta Rays showsed up, not nearly as many and same for the blue crabs.
Of course, during the Summer you have almost constant onshore winds all through Summer, gradually building through the day and starting onshore SE moving to S and then SW and dying off in the evening. That seabreeze does bring in some Sargasso seaweed. That's the type that feels more course than the June Grass and has airfilled pockets in the plant that cause it to stay on top of the water. It doesn't smell like the June Grass does though. The June Grass will smell bad and it also picks up Jelly Fish tentacles and Sea Nettles which will sting you even though you don't see a Jelly Fish around.
Does anyone know if there is any place on the web that has documented sea and plant life patterns for this area from year to year and recorded whether patterns and water temperature? I bet you could learn a lot about when is best to come. But, I can tell you for sure end of Summer and into the Fall is the best time if you like warm clear water and less crowded beaches.
