/in"treuh koh"steuhl, in'-/
a mostly inland water route, partly natural and partly artificial, extending 1550 mi. (2500 km) along the Atlantic coast from Boston to Florida Bay (Atlantic Intracoastal Waterway) and 1116 mi. (1800 km) along the Gulf coast from Carrabelle, Fla., to Brownsville, Tex. (Gulf Intracoastal Waterway): constructed to protect small craft from the hazards of the open sea.