One of the interesting things we learned in the fluids lab at UNC was that the oil coming out of the BP Macando well was probably coming out at between 100 and 300 degrees F meeting water that was just above freezing. that alone combined with its great velocity would be enough to cause it to entrain sea water and become neutrally or negatively buoyant and form cloud layers. The professors told us that the smaller the droplets of oil the longer they will persist in the ocean in stratified layers. BTW -- The oil was hot because it was coming from so far deep in the earth. Great thanks to UNC Chapel Hill and Professor Roberto Camassa and Professor Rich McLaughlin.