AICW / ICW / or "The Ditch"
The Atlantic Intracoastal Waterway (AICW / ICW) or "The Ditch" as many refer to it provides the mariner with a continuous, and for the most part, protected passage just inside the Atlantic Coast and through the Florida Keys. Beginning at mile marker (MM "0.0") 36°50’54” N / 76°17’54” W in Norfolk, VA the Atlantic Intracoastal Waterway stretches 1,243.8 SM (1080.8 NM) south to Key West, FL.
The AICW, made up of both natural and man-made canals, rivers, bays, and sounds; is primarily used by pleasure craft. However, many commercial light-draft vessels as well as smaller tugs and tows also make use of the Atlantic Intracoastal Waterway in an effort to avoid long open ocean passages.
In the Virginia section of the AICW, (2) Routes are available to the mariner beginning around (MM 7.0) in Virginia where they split. Route #1, the most common route used and providing deeper water, follows the Albemarle and Chesapeake Canal to Albemarle Sound. Route #2, the alternate route, is through Great Dismal Swamp Canal to Albemarle Sound. Both Route #1 and Route #2 rejoin in the vicinity of (MM 79.0) in North Carolina.
Manasquan, NJ considered by many to be the unofficial northern end of the AICW allows smaller boats to cruise south through New Jersey’s largely unimproved channels. Caution is warranted however, since much of New Jersey’s ICW is shoal with a number of fixed bridges having a limiting vertical clearance of 35 feet. Most, if not all, boats (power or sail) bound for warmer climes elect to sail coastwise rather than attempt the NJICW.
From New Jersey, a choice of (2) routes are available. The inside route will take you through the Delaware Bay, the C&D Canal, and the Chesapeake Bay or you can elect to sail coastwise to the Chesapeake Bay Entrance. Both routes leading to Norfolk, VA and (MM 0.0,) the official start of the Atlantic Intracoastal Waterway.
Aids to Navigation
Intracoastal Waterway Aids to Navigation (ATONS) show a characteristic yellow marking of either a square or a triangle as well as the normal red and green coloring of the familiar lateral buoyage system. These yellow squares or triangles distinguish them from aids to navigation (ATONS) marking other waters.
The rule is: When proceeding south on the Atlantic Intracoastal Waterway (Norfolk, VA to Key West, FL) or west on the Gulf Intracoastal Waterway (Ft. Meyers, FL to Brownsville, TX)
- “Yellow Squares are ALWAYS kept to port”
- “Yellow Triangles are ALWAYS kept to starboard”
Regardless of the color of the mark!
This becomes important when the ICW temporarily merges with or crosses a second navigable channel.
Lights and daybeacons should not be passed close aboard because those marking dredged channels are usually placed back from the bottom edge of the channel and others may have rip-rap mounds around them to protect the structures.
The following (14) NOAA charts cover the entire length of the AICW from (MM 0.0) to Key West, FL.
Distances and Mileages
All distances along the Atlantic Intracoastal Waterway are given in statute miles unless otherwise noted. Statute miles are used in order to conform to the distances shown on the small craft charts typically used along this route.
The Federal Project Depth for the AICW via Albemarle and Chesapeake Canal (Route #1) provides for a least depth of 12 feet from Norfolk, VA, (MM 0.0) to Fort Pierce, FL, (MM 965.6.) From Fort Pierce south to Miami, FL, (MM 1089.0) the Federal Project Depth is 10 feet. From Miami south and west to Key West, FL (MM 1243.8) Project depth is 7 feet.
DO NOT confuse "Federal Project Depth" with "Controlling Depth" or for that matter with the actual depth of the water that is available at the time you transit any given channel.
Keep in mind that the Atlantic Intracoastal Waterway south of Miami has only been completed as far as Cross Bank (MM 1152.5); the remainder has been put on hold. While no work has been performed south of Cross Bank, a channel, marked with standard ICW markings, leads from Cross Bank to Big Pine Key along the northwesterly side of the Florida Keys. In the vicinity of Bethel Bank, the route splits; going either north through Florida Bay or south through Hawk Channel to Key West.
At last count (01/01/2016,) a total of 144 bridges cross the Atlantic Intracoastal Waterway between (MM 0.0) in Norfolk, VA and (MM 1089.0) in Miami, FL. Surprisingly, these bridges are almost evenly split between high level fixed bridges and operating bridges.
The minimum overhead clearance of fixed bridges over the AICW is 56 feet at the Julia Tuttle Bridge in Miami, (MM 1087.1.) This means vessels requiring more than 56’ bound for Miami must leave the Atlantic Intracoastal Waterway at Fort Lauderdale (Port Everglades) (MM 1066.5) and sailing coastwise, re-enter at Miami (Government Cut) at (MM 1089.0.)
All operating bridges on the AICW guard either channel 09 or 13 as their working channels depending on the state they are located in.
It should be noted that in recent years there has been ongoing bridge construction the length of the ICW in an effort to replace many of the existing operating bridges. As these new high level (65’+) bridges have been completed many of the operating bridges they have replaced are being demolished and of those that remain, many are having their operating schedule restrictions modified or lifted completely.
The minimum authorized clearance of overhead cables crossing the AICW is 68 feet at Snows Cut, (MM 295.8,) in Federal Point, NC. There is also an overhead cable car found at (MM 356.4) in Myrtle Beach, SC having a least clearance of 67 feet under the low point of travel of the car.
Caution - Many of the overhead cables over the waterway carry high voltage, and an extra margin of safety should be allowed when the weather is threatening.
Great Bridge Lock (MM 11.5) is the only lock on the Intracoastal Waterway between Norfolk and Key West via Albemarle and Chesapeake Canal (Route 1.) It is 600 feet long (530 feet usable), 75 feet wide (72 feet usable), 16 feet over the sills, with a lift of 2.7 feet.
For those using the Great Dismal Swamp (Route #2,) you will encounter (2) locks one at Deep Creek (MM 10.6) and the other at South Mills (MM 33.0.) Both Locks are 300 feet long, 52 feet wide, 12 feet over the sills, and a lift of 12 feet.
Under normal conditions the mean range of tide in the AICW is from non-tidal just south of Great Bridge Lock to about 7 feet throughout most of Georgia. In many sections, the height of the tide is heavily influenced by the force and direction of the wind.
Atlantic Intracoastal Waterway - Bridge & Lock Schedules
The following pages list the bridges & locks; their schedules, and restrictions along the Atlantic Intracoastal Waterway (AICW) from Norfolk, VA to Miami, FL.
In addition to each state's bridge list, the complete AICW (Norfolk to Miami) bridge operating schedule can be downloaded for your personal and private use. The ZIP file contains the schedule in Adobe (.pdf) file format.
These lists are believed to be accurate as of January 2017. If any errors or omissions are noted, please e-mail us at with any corrections or recommendations.