Have you ever looked at a map of the United States, or any map of the Gulf Coast or Atlantic States, and seen a long canal called the Intracoastal Waterway? Ever wonder what it is? The Intracoastal Waterway is a navigable toll-free shipping route extending 3000 miles from Brownsville, Texas, to Boston, maintained by the federal government and usable by most deep-draft vessels.
Why was it necessary?
In the 19th and early 20th centuries, navigators were faced with a problem; to ship supplies by sea to another American location, they had to follow the coasts of the Gulf of Mexico and/or the Atlantic Ocean. However, these voyages were often fraught with peril, from offshore storms, shallow reefs, and high waves. A better system was needed, to reduce the hazards of navigating the coasts and to shorten distances.
The American government mulled its options, and finally passed the River and Harbor Act. Approved January 21, 1927, the act authorized the establishment and maintenance of an inland waterway in general seventy-five feet wide and eight feet deep at mean low water, following a coastal route from Brownsville, Texas, to New York. However, work on this project was often delayed or done piecemeal; until the late 1970's, continuous projects were initiated by the Army Corps of Engineers to deepen and widen existing channels, or create new ones.
Although the plans called for a continuous route from Brownsville to New York, it required a canal through the Florida peninsula, and this was never created. Thus, the Intracoastal waterway is divided into two sections; the Gulf Coast section, running 1,100 miles from Brownsville, Texas to Apalachee Bay, Florida; and the Atlantic section, running 1,900 miles from Key West, Florida to Boston, Massachusetts.
Geography of the Waterway
The Intracoastal Waterway was designed to utilize as much as possible pre-existing sounds, bays, lagoons and rivers. Luckily for engineers, almost the entire Texas section of the Waterway already had a long string of placid bays and lagoons, stretching from Padre Island to Galveston. From Galveston, the Waterway utilizes a series of man-made canals to Plaquemines Parish. From there, the Plaquemine - Morgan City waterway provides direct connection west of New Orleans with the extensive Mississippi River valley system of inland waterways, and the Harvey Lock at New Orleans offers a direct link with the Mississippi River. From New Orleans, the Waterway utilizes inland bays until it reaches the Gulf Coast's terminus, Apallachee Bay in Florida.
On its Atlantic route, the Waterway utilizes much more man-made canals and passages, including the Chesapeake and Delaware canal, the Chesapeake-Albemarle canal, and, further north, the Cape Cod canal. In the Dismal Swamp canal of Virginia and North Carolina, the Waterway reaches its lowest depth at 6. 1 feet, though it is still navigable.
Throughout Florida, Georgia and South Carolina, the waterway follows behind the many islands there, and further north it follows Chesapeake Bay north to the Chesapeake-Delaware canal, where it follows the New Jersey seaboard to New York.
The Intracoastal Waterway is heavily used by industry to ship goods and raw materials, however certain industries are predominant, such as:
North of Norfolk, Virginia, the Waterway is heavily used by oceangoing vessels, such as cargo ships and barges, but south of Norfolk the waterway is primarily used by pleasure boats and ships headed to and from Florida.
An interesting use of the Waterway occurred in WWII. Allied submarines and cargo ships were often beseiged by German U-Boats, so during the war the route became a safe refuge for ships and submarines, as well as basic industrial shipping, as the U-Boats would often prowl up and down the coast looking for targets.
Sources: Britannica 2002, http://www.aicw.org/history.htm, http://www.toad.net/~tdove/icw.html