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What Is the Intracoastal Waterway (ICW)?

What the Intracoastal Waterway is: the protected route along the US Atlantic and Gulf coasts, how boaters use it, mile markers, and the marinas that serve it.

NP
Nayan Patel
Founder, Marine OS
Published June 28, 20266 min read

The Intracoastal Waterway, almost always shortened to ICW, is a roughly 3,000-mile route along the eastern and southern coasts of the United States that lets boats travel in mostly protected water instead of running offshore in the open ocean. It is part natural, made up of bays, rivers, and sounds, and part built, stitched together with dredged channels and canals. For a huge number of boaters, it is the road they take to move a boat up and down the coast.

If you run a marina anywhere along this corridor, the ICW is also a steady source of transient business. This guide explains what the waterway is, how boaters use it, and why it matters to the marinas along its banks.

Key takeaways
  • The Intracoastal Waterway is a protected, roughly 3,000-mile boating route along the US Atlantic and Gulf coasts.
  • It lets boats travel in sheltered water instead of running offshore, which is safer and more comfortable.
  • Boaters track their position by mile markers, measured from Mile 0 in Norfolk, Virginia.
  • Seasonal migrations south in fall and north in spring create predictable waves of transient traffic.
  • Marinas along the ICW earn significant revenue from transient cruisers who book stops as they go.

#The Atlantic and Gulf sections

The ICW has two main parts. The Atlantic Intracoastal Waterway runs from Norfolk, Virginia, south around Florida. The Gulf Intracoastal Waterway runs along the Gulf coast from Florida to Texas. Together they let a boater travel much of the eastern and southern seaboard without venturing into the open Atlantic or Gulf for long stretches, which is the whole appeal: protected water is safer, calmer, and far more forgiving than the ocean.

#How boaters find their way: mile markers

Position on the Atlantic ICW is measured in statute miles from Mile 0 at Norfolk, increasing as you head south. Cruisers describe locations by their statute mile, as in "anchored around Mile 568," and marinas advertise their mile marker so passing boats can find them. Alongside mile markers, boaters use charts and a route planner to set their day, which is why our marine route planner and passage planning guide pairs naturally with ICW travel.

#The snowbird migration

The ICW has a rhythm. In autumn, a wave of boats heads south toward Florida and the Bahamas to escape northern winters, and in spring the same fleet heads back north. These migrations create predictable surges of transient traffic, and a marina positioned along the route sees its docks fill with cruisers who need a slip for a night or two as they move. Understanding that traffic is the first step to capturing it.

#Why the ICW matters to marinas

For a marina on the waterway, transient cruisers are real money. They arrive needing fuel, a slip, power, and often a meal ashore, and they choose where to stop based partly on which marinas they can book quickly. A cruiser deciding tonight's stop is on a phone, so a marina that takes online slip reservations captures business that a phone-only office loses. The economics of this short-stay traffic are covered in our guide to transient slip reservation software, and the charges involved in our explainer on dockage fees.

3,000 miles
The approximate length of the Intracoastal Waterway along the US coast
Mile 0
The Atlantic ICW is measured in statute miles starting from Norfolk, Virginia
For marinas on the route

If your marina sits on the ICW, transient cruisers are a core revenue stream, and the easiest way to capture them is to let them book and pay from a phone as they travel. Marine OS is cloud-based marina software, in early access, that handles online booking and payments for exactly this kind of traffic.

Capture passing cruisers

Let ICW boaters book your slips online

Marine OS lets transient cruisers book and pay for a slip from their phone as they travel the waterway. It is in early access with a 7-day free trial, no credit card required.

Book a demo

7-day free trial. No credit card required.

#Frequently asked questions

Frequently asked questions

The Intracoastal Waterway runs roughly 3,000 miles in total along the US Atlantic and Gulf coasts. The Atlantic ICW runs from Norfolk, Virginia, south around Florida, and the Gulf ICW runs from Florida to Texas, letting boats travel much of the seaboard in protected water.

Planning a coastal trip? See our marine route planner and passage planning guide, and if you run a marina on the route, how to take online slip reservations.

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NP
Written by

Nayan Patel

Founder, Marine OS

Nayan is the founder of Marine OS, modern marina management software currently in early access with marina operators. He writes about marina operations, technology, and the economics of running a marina business.

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