New Jersey Intracoastal Waterway

The New Jersey Intracoastal Waterway (NJIWW), sometimes called the New Jersey Intracoastal Canal or NJICW, is a sea‑level inland waterway running along the Atlantic coast of New Jersey. It is part of the Atlantic Intracoastal Waterway system and provides a protected route for commercial and recreational vessels between Manasquan Inlet in the north and Delaware Bay in the south. The waterway was adopted as a federal navigation project in 1939 and today extends about 117.7 statute miles (189 km), with most of the channel maintained to a depth of approximately 6 feet (1.8 m) at mean low water; the Cape May Canal section is maintained deeper at roughly 12 feet (3.7 m).^[1] The NJIWW serves marinas, the Cape May/Wildwood commercial fishing fleet, the U.S. Coast Guard and the Cape May–Lewes Ferry, and is popular among boaters and anglers.

The NJIWW begins at Manasquan Inlet, the unofficial northern terminus of the Intracoastal Waterway, where the Manasquan River enters the Atlantic Ocean. From the inlet it follows the river for about 2 mi (3 km) and then turns south into the Point Pleasant Canal. After exiting the canal, it continues through the northern reaches of Barnegat Bay, winds past numerous inlets, islands and marshlands, and proceeds south through a succession of bays, lagoons and thoroughfares along New Jersey's barrier‑island coast (including Little Egg Harbor, Great Bay, Absecon Inlet, Great Egg Harbor Bay and Townsends Inlet). It finally enters Cape May Harbor and then, via the Cape May Canal, reaches Delaware Bay about 3 mi (5 km) north of Cape May Point.^[1] Measured southbound, mile marker 0.0 is at Manasquan Inlet and mile 117.7 is at the western entrance to the Cape May Canal; cruising guides describe the route’s length as approximately 117.7 statute miles (102.3 nautical miles).^[2]

The concept of an inland waterway along New Jersey’s coast dates to the early 20th century. Congress adopted the New Jersey Intracoastal Waterway as a federal project in 1939, and construction was largely completed by 1940.^[1] The original project provided a channel through coastal inlets and bays and maintained an 8‑ft‑deep (2.4 m), 200‑ft‑wide (61 m) channel to connect Barnegat Light Harbor with the main route.^[3] In 1991, design improvements at Barnegat Inlet added a new south jetty, deepened a navigation channel to 10 ft (3.0 m) below mean low water and expanded the channel width to 300 ft (91 m).^[3]

The NJIWW is administered by the U.S. Army Corps of Engineers, Philadelphia District. Most of the waterway is maintained to a depth of about 6 ft (1.8 m) MLW, with the Cape May Canal section maintained to 12 ft (3.7 m) MLW.^[1] Shoaling is a recurring challenge, and some sections—especially south of Barnegat Bay and between Cape May and Atlantic City—may have depths as shallow as 3.5 ft (1.1 m).^[4] Maintenance dredging is funded through federal appropriations, and dredged materials are increasingly placed on eroding marshes and shorelines as part of beneficial‑use projects.^[1]

Navigation aids along the NJIWW follow the Atlantic Intracoastal Waterway marking system: markers carry yellow triangles or squares to indicate the ICW channel. When travelling south, vessels should keep yellow triangles to starboard and yellow squares to port regardless of the marker’s underlying color.^[2] At inlet intersections the marker colors reverse. Shoaling, narrow channels and congested weekend traffic require careful attention; boaters drawing more than 3 ft (0.9 m) are advised to time their passage for rising tides, and those drawing over 3.5 ft (1.1 m) may need to use the ocean route between Cape May and Atlantic City.^[4][5] The controlling vertical clearance between Cape May and Atlantic City is about 35 ft (10.7 m).^[4]

The waterway traverses sensitive coastal ecosystems such as salt marshes, lagoons and barrier‑island bays. Boat traffic and dredging operations have raised concerns about erosion, habitat loss and water quality. Recent Corps projects have used dredged sediment to rebuild marshland and enhance shoreline resilience at sites near Mantoloking, Mordecai Island and Seven Mile Island.^[1] Sections of the waterway fall within migratory‑bird flyways and provide habitat for diverse wildlife, so environmental stewardship and adherence to no‑wake zones are important.

The NJIWW supports both commercial and recreational activities. It provides access to the East Coast’s largest commercial fishing fleet at Cape May/Wildwood and to nine U.S. Coast Guard stations (including the Coast Guard Training Center).^[1] The Cape May–Lewes Ferry uses the Cape May Canal segment; closing the canal would require a vehicle detour of about 183 mi (295 km) around Delaware Bay.^[1] Recreational boaters use the NJIWW for cruising, fishing, birdwatching and access to shore‑town marinas.^[4]

• Atlantic Intracoastal Waterway
• Cape May Canal
• Manasquan River
• Point Pleasant Canal