What is the Intracoastal Waterway?
Our trip around America’s Great Loop would not be possible without the Intracoastal Waterway, or ICW.
The ICW is a 3,000 mile series of inland waterways that runs along the east coast of the US from Massachusetts to Florida and then again along the Gulf Coast all the way from Florida to Brownsville Texas. The ICW connects a series of natural sounds, bays and rivers plus a number or manmade canals.
Apart from a section between Florida’s eastern panhandle and upper peninsula the ICW is a continuous, protected waterway that provides a navigable route along the coast with minimal risks or hazards of traveling in open ocean.
It’s Intracoastal NOT Intercoastal!
Many people call it the Intercoastal Waterway when in fact it is the Intracoastal Waterway. I made this mistake for many years until starting to plan our loop journey. When I looked it up, I learned that the prefix intra- means "within" as in happening within a single thing, while the prefix inter- means "between" as in happening between two things.
The history of the ICW goes back to the 1800s when the US senate commissioned a plan to connect waterways from Massachusetts to Georgia. While this initial plan was not implemented, the ICW was developed through different projects during the 19th century. The invention of the diesel engine followed by the passing of the Panama Canal Act, both in the early 20th century led to an increase in the importance of the US waterways for commercial uses. By the 1940s the ICW was complete and today federal law provides for the waterway to be maintained at a minimum depth of 12 feet for most of its length.
Early plans for the ICW included additional sections across Florida. The first would have connected Florida’s peninsula and panhandle, from Tarpon Springs to near Carrabelle. The second planned extension was a canal across northern Florida connecting the Gulf of Mexico to the East Coast. Below is a map of the Cross-Florida canal with highlights of the sections completed and not completed.
The ICW was initially built to facilitate safe commercial marine traffic along the coast of the US to augment rail and road traffic however in many places it has evolved to be an important waterway for recreational boaters. For persons traveling America’s Great Loop the trip would in many ways not be accessible to many boaters if not for the ICW.
We have now traveled approximately 1,600 miles since the start of our journey and all but about 100 of it has been along the Gulf Intracoastal Waterway, GIWW and Atlantic Intracoastal Waterway, AIWW. Our shakedown cruise started in Galveston Bay then along the Texas and Louisiana coasts across the Mississippi River into Mississippi and then across Mobile Bay into Alabama. On this route 90% of the boat traffic that we encountered was commercial barge traffic, more specifically tugboats pushing large barges filled with everything from chemicals to coal to scrap metal.
As we started the first leg of our loop journey we continued on the GIWW to its end in Carrabelle on the east end of Florida’s panhandle. We picked up the AIWW in Stuart, on the east coast of Florida. We will be on the AIWW on and off for the coming year as we travel up and down the east coast.
All along the GIWW and AIWW there are bridges of all types and sizes, roadway and railroad, draw bridges, lift bridges, swing bridges and pontoon bridges.
As we traveled along the ICW we monitor vessel traffic using AIS, which stands for Automatic Identification System. AIS is a radio based system that transmit relevant information about a vessel including size and speed and is invaluable when maneuvering in smaller waterways as is often the case on the ICW. Technically AIS is required for all commercial vessels weighing more than 300 gross tons or over 65 feet as well as certain passenger vessels and ships carrying hazardous cargo however it is a good idea for anyone traveling extensively on the ICW to have AIS.
With AIS I can identify and subsequently communicate with tug captains and ask them for direction where they want us to pass as we are much more maneuverable. We have an AIS transmitter on Odysea II and therefore other vessels can identify us and communicate to us specifically. Overall this is a professional courtesy that all parties appreciate.
All along the ICW are towns and cities, many of which present a different perspective and character from the water. We especially appreciate the local municipalities that have built waterfronts and marinas catering to ICW recreational traffic. These efforts have left a positive image with us that would not have been possible if we visited via land. We are looking forward to adding to our list of favorite stops as we continue along the ICW.