There's an expensive and time-consuming fad sweeping America's ports: dredging. This is the process by which ports dig up the bottoms of their channels, either to maintain depth or go even deeper. In the last 5-10 years, dredging has taken ports by storm. To take just two examples: the Port of Boston recently completed a $350 million project to dredge the channel from 40 to 51 feet, and the Port of Miami requested a second dredge in 2018, just three years after completing a $205 million project to deepen their channel from 42 to 50 feet. They're far from the only ones, so why are ports in a such a race to dig deeper?