Intracoastal Waterway, navigable toll-free shipping route, extending for about 3,000 miles (4,800 km) along the Atlantic Ocean and Gulf of Mexico coasts in the southern and eastern United States. It utilizes sounds, bays, lagoons, rivers, and canals and is usable in many portions by deep-draft vessels. The route is federally maintained and is connected to inland waterways in many places. It was originally planned to form a continuous channel from New York City to Brownsville, Texas, but the…