Typically, SCUBA diving is peaceful and quiet. The only sound is your own breath. But on that day, in the idyllic marine habitat off Miami Beach, the very reef that makes this part of the world iconic, was darkened with swirling sediment clouds. The ocean floor was gray and flat -- the reef looked more like a moonscape than a vibrant and functioning ecosystem. All of the reef’s colors and its natural nooks and crannies were covered by fine sediments that fell like a volcano’s ash onto everything that lay below. Something was clearly very wrong. As we dove, the current was ripping through the nearby shipping channel, requiring all of our strength to search for the threatened staghorn corals in the area. A constant whirring and crunching sound nearby was so loud that it caused vibrations that shook our chests. It was 2015, and although I had been a scientific diver for nearly a decade, this was unlike anything I had experienced before. Diving next to an active dredging operation was a new and intense experience.