"The U.S. Marine Transportation System (MTS), the waterborne element of the National Transportation System, is complex, decentralized, and made up of an array of interdependent components, including ports, terminals, vessels, channels, intermodal-connectors and those who use them. [...] From the food we eat to the clothes we wear, from the cars we drive to the oil and natural gas we use to heat and cool our homes. The MTS is an integral part of the national economic supply chain. The U.S. Census Bureau has predicted that the U.S. population will increase 30 percent between 2015 and 2060--The MTS will need to be able to accommodate the corresponding increase in port calls to support our way of life."
U.S. Committee on the Marine Transportation System: http://www.cmts.gov/