The Gulf Intracoastal Waterway (GIWW) is the portion of the Intracoastal Waterway located along the Gulf Coast of the United States. It is a navigable inland waterway running approximately 1,300 mi (2,100 km) from Saint Marks, Florida, to Brownsville, Texas.
The waterway provides a channel with a controlling depth of 12 ft (3.7 m), designed primarily for barge transportation. Although the U.S. government proposals for such a waterway were made in the early 19th century, the Gulf Intracoastal Waterway was not completed until 1949.

Quelle: Wikipedia