The red and green markers are standard boating navigation aids that show you where the safe channel is and which side you should keep to while traveling.

Basic meaning

  • Red markers: Mark the right (starboard) edge of the navigable channel when you are coming in from open water or going upstream.
  • Green markers: Mark the left (port) edge of the navigable channel when you are coming in from open water or going upstream.

A common memory phrase is:

“Red right returning” – keep red on your right when returning from sea or going upstream.

Numbers and mixed markers

  • Red markers usually have even numbers; these numbers increase as you move inland or upstream.
  • Green markers usually have odd numbers; these also increase as you move inland or upstream.
  • Red–green combination markers (junction buoys) sit where two channels meet and show the preferred route: the color on top indicates which side is the main channel.

Quick practical example

If you’re steering a boat from the ocean into a harbor or up a river:

  • Keep red markers on your right-hand side.
  • Keep green markers on your left-hand side.

Do that, and you’ll stay within the intended safe channel most of the time.

Information gathered from public forums or data available on the internet and portrayed here.