an improved navigable waterway along the Gulf Coast of the United States, extending from Apalachee Bay, Florida, westward to the Mexican border at Brownsville, Texas, a distance of more than 1,100 miles (1,770 km). In part artificial, the waterway consists of a channel paralleling the coast behind barrier beaches, the channel being linked by a series of canals. The Gulf Intracoastal Waterway is an important route for barges, and several sections of it furnish access to major gulf ports for oceangoing vessels. See Intracoastal Waterway.