Marine Transportation System.

According to the Department of Transportation, when cargo is transported by water within the United States, 95 percent of the time it involves the Marine Transportation System (MTS). This comprehensive system resulted from years of water transport development involving such U.S. organizations as the Coast Guard, Maritime Administration, Army Corps of Engineers, NOAA, and Environmental Protection Agency.

The U.S. Marine Transportation System moves people and goods via coastal and inland waterways. The diversity of the system’s users is illustrated in this photograph of the Port of Tacoma, Washington, where a sea kayaker shares the water with a container vessel. (Container cranes and Mount Rainier are visible in the background.)

The MTS is a complex and diverse national network of waterways, ports, and intermodal landside connections that allows various modes of water-based transportation. The system includes: navigable waterways (such as the Great Lakes-St. Lawrence Seaway); publicly and privately owned commerce-carrying vessels; over 3,500 bulk oil transfer facilities; more than 350 ports located at approximately 4,000 marine terminals; about 40,000 kilometers of navigable channels; more than 235 locks and dams at over 190 locations; shipyards; rail yards; vessel repair facilities, over 10,000 recreational marinas; and a trained labor staff that operates and maintains the entire infrastructure. Users of the waterway system each year include 70,000 port calls for commercial vessels, 110,000 fishing vessels, and 20 million recreational vessels.