We had the same experience at Paradise Beach on one of our cruises and it was also during the month of May. The water was black and filthy and there was no avoiding whatever was in the water. We never even put a toe in the water and like you, had paid dearly for our family group. We asked some of the wait staff what the problem was and they did not have an answer. They figured we were unwilling captives and kept pushing the alcoholic drinks and food which we did not order...stayed for a short period of time then took a taxi back to the dock. If we had known the condition of the water, we would never have gone there. Checked Paradise Beach off my list forever, there is no way I'll ever go back there.