The brown areas are water that is tinted brown by the tanic acid drawn out of the dead mangrove leaves. The green are the red mangroves. I have not been exactly there, but it is similar to other places in the glades I have been. Very mucky, from years of deterious material build up. Proably a foot or less of water. I doubt if there is any actaul ground their above sea level. Very sure that was never a site used by the indigeous tribes. Several of your other post show natural features also.