Chapter 6: Navigation Aids

The Intracoastal Waterway

The Intracoastal Waterway (ICW) runs along the Atlantic Coast and the Gulf of Mexico. It is a series of parallel channels that span New Jersey to Texas and is noteworthy, not only for its size but also because of the special markers found in its waters.

Markers, in the Intracoastal Waterway, are similar to the markers found in other U.S. waterways, but also carry yellow symbols. These symbols indicate the route of the ICW and which side of the marker to must pass on. These symbols are important because they override the shape and color of the lateral marker to which they are attached. In other words, always follow these yellow signals and their directions when boating on the Intracoastal Waterway.

Yellow Square

Yellow Square:

When heading north to south, keep this marker on the port side.

Yellow Triangle

Yellow Triangle:

When heading north to south, keep this marker on the starboard side.

The Western Rivers System and Mile Markers

The Western Rivers System and Mile Markers:

When boating on the Mississippi River, or its tributaries above Louisiana, we will notice a difference from the sequential numbering system found in the U.S. Aids to Navigation System.

These waters use the Western River System and in this system "mile markers," which indicate the distance to the mouth of the river, are placed below Day-Markers. These mile markers can let one know whether traveling upstream or downstream and can help find one’s location on a nautical chart.