The map shows some (not all) U.S. ports, highlighting the internal ports in yellow and the coastal deep-draft ports in light blue. "A strong majority of coastal navigation infrastructure features deep-draft ports, which are greater than 14 feet of draft. Coastal deep-draft navigation infrastructure typically pertains to coastal ports and harbors engaged in international trade. In most cases, it is also associated with the distribution of internationally traded goods to multiple US coastal ports and harbors, such as Miami and New York." Source: IWR Report 2013-R-09, "Value to the Nation of the U.S. Army Corps of Engineers’ Civil Works Programs: Estimates of National Economic Development (NED) Benefits and Revenues to the U.S. Treasury for 2010."