Great Loop ICW signs and Day markers
Cruising
America's Great Loop
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The Atlantic Intracoastal Waterway runs most of the length of the entire Eastern Seaboard. It is
toll-free for pleasure boats and it is a significant portion of America's Great Loop.
The Atlantic ICW (for cruising purposes) serves ports from Atlantic City, NJ to Key West, FL. This
route is linked by man-made canals including the Chesapeake and Delaware or C&D canal, and
Chesapeake-Albemarle Canal, and the lowest "controlled" depth is 6 feet in the Dismal Swamp Canal.
The heaviest commercial traffic (oceangoing vessels and barges) are concentrated around the
industrial areas of Norfolk, Va;
The Gulf Intracoastal Waterway serves ports for more than 1,100 miles between Brownsville,
Texas, to Carrabelle, FL. At its eastern end, (Carrabelle, FL) the Gulf ICW is not directly connected
with its Atlantic counterpart. To make this connection, you will need to either hop-scotch your way
around, or cross a portion of open waters in the Gulf of Mexico, and then make your way south down
to and through the Okeechobee Waterway in southern Florida.
The heaviest commercial activity on the Gulf ICW is centered at New Orleans and extends to the
Tennessee–Tombigbee River System at Mobile Bay, and west to Galveston. The Harvey Lock at New
Orleans furnishes a direct entrance to and from the Mississippi River.  
Over all, while some may envision the Gulf and Atlantic Intracoastal Waterways as a  
superhighway on the water for boats, speed wise it is not quite that. For the most part your speed will
be limited, but it is easy to navigate your way along its miles of wide channels and narrow canals.
Most of it by far, offers lots of very interesting things to do and see along the way.
The requirement for a waterway dates back to the Revolutionary War in the US, but it was not
until 1808 that a proposal was made for a coordinated ICW project. In 1909 Congress passed the
Rivers and Harbors Act authorizing the US Army Corps of Engineers to complete surveys for an
Intracoastal waterway system. The Corps of Engineers is still responsible for the maintenance of the
waterway.  Since Obama took office however, funds and personnel for  have been cut.  While the
controlling depth is supposed to be 12 feet at mean low water along the ICW, it is now 9 to 10 feet in
most areas and close to 6 feet in some.  
The Intracoastal Waterways consist of natural inlets, salt-water rivers, bays, and sounds; other parts are man-made
canals. All together, they are a vital part of cruising America's Great Loop by providing a safe navigable route along Gulf and
Atlantic without the hazards of traveling long distances across the open seas.  Additionally, you are never that far from land
and most of the time you are hardly a stones throw from it.
::   Navigating the ICW   ::
The next leg of your journey is the Hudson River - click NEXT
On America's Great Loop, you will have a brief encounter with the ocean in
two locations
.
    While most all the talk is over the Gulf crossing, Those that have actually done the Loop know we have
to  'go out' at the end of the New Jersey Intracoastal Waterway. But fret not, as several Bays and Sounds are
likely to be much rougher than this little hop in the ocean. Crossing Albemarle Sound for example, has
always caused us more anxiety than the ocean.  
    The NJ ICW ends at Manasquan Inlet in NJ. Here, we are forced to travel "outside" to reach Sandy Hook
Bay and into New York Harbor.
    You have two choices when you leave the Delaware River - One you can 'go out' about a mile into the
Atlantic and turn north toward NY for 158 miles. Or you can continue on the NJ ICW for 118 miles, and take a
short 22 mile run to Sandy Hook Bay. The only issue here is your vessel's draft. The NJ ICW is known for it's
shallow waters, shoaling, winds, and tidal changes. If your boat has a draft of 4' 6" or less you should be
fine. If your draft is over 5' it might be touch & go, and you might want to consider the outside route from
Delaware Bay.
    While you may feel a bit apprehensive over 'going out' - Don't be! You simply need to be patient and wait
for the best wind and weather conditions. If you do, it will pay off with a smooth Atlantic leading to the Bay.
Fact is, (as you will discover) it is not the Atlantic so much as it will be the traffic. Once past Sandy Hook and
into the Bay you are boating into one of the busiest seaports in the world. Soon enough, you will see the
New York skyline and the Statue of Liberty, and what an emotional site that is to see from your very own boat.
    Most Loopers with a shallow draft take the inside route to Manasquan Inlet. From there, It is only 22 miles
to Sandy Hook Bay. There are lots of Marinas in the area, fuel stops are not a problem, So if you take the
NJICW from Cape May you might consider lightening your vessel (and your draft) by not topping off your
tanks until you reach Manasquan.  
The New Jersey Intracoastal Waterway (NJICW)
At the end of the Atlantic ICW, we have an area known as "the New Jersey Intracoastal
Waterway".  The New Jersey Intracoastal Waterway (NJICW) stretches about 118 miles from Cape
May at Delaware Bay to the New Jersey Manasquan Inlet, which is located about 40 miles south of
New York City and about 20 miles south of Sandy Hook Bay..
Cruising the Intracoastal Waterway - ICW
www.captainjohn.org                                                                      - Cruising America's Great Loop - Once Around Is Not Enough -
Reason #1, 2 & 3 you need two excellent pair of binoculars - One for you, one for your 1st Mate, or a spare.
Often, especially at a distance, those tiny yellow stickers are very hard to see.
On the Gulf & Atlantic ICW
If you follow the signs (Day Markers)
it is impossible to get lost.

Well. . . Almost impossible!
www.captainjohn.org
       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 coast wise 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 coast wise 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 "Red Right Return to Texas"  (officially, Norfolk to Brownsville, TX).
However - “Yellow Squares are ALWAYS kept to port” and “Yellow Triangles are ALWAYS kept to starboard” Regardless of the color of the marker!
As they will change when the ICW temporarily merges with or crosses a second navigable channel.
Distances and Mileages
All distances along the Atlantic Intracoastal Waterway (and Inland rivers are given in statute miles unless otherwise noted. Statute miles are given all
around your Great Loop route. You only even have the option of Nautical miles on the Great Lakes where both Statute & Nautical are used.
Channels
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.
Bridges
At last count (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.
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.
Overhead Cables
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.
Locks
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.
Tides
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.