Lateral Markers: Colors and Numbers

These navigation aids mark the edges of safe water areas; for example, directing travel within a channel. The markers use a combination of colors and numbers, which may appear on either buoys or permanently placed markers.

The colors and numbers have the same meaning regardless of the kind of buoy or marker on which they appear.

Red Colors, Red Lights, and Even Numbers: These mark the edge of the channel on your starboard (right) side as you enter from the open sea or head upstream. Numbers usually will increase consecutively as you return from the open sea or head upstream.

Green Colors, Green Lights, and Odd Numbers: These mark the edge of the channel on your port (left) side as you enter from the open sea or head upstream. Numbers usually will increase consecutively as you return from the open sea or head upstream.

Red and Green Colors and/or Lights: These are placed at the junction of two channels to indicate the preferred (primary) channel when a channel splits. If green is on top, the preferred channel is to the right. If red is on top, the preferred channel is to the left. These also are sometimes referred to as “junction buoys.”