Preferred-channel marks

These are horizontally banded red and green.

The uppermost color gives the mark its lateral significance for the preferred channel.

Red on top

Treat it as a red mark for the preferred channel.

When proceeding in the conventional direction, keep it to starboard. The preferred branch is therefore on the other side of the mark.

Green on top

Treat it as a green mark for the preferred channel.

Keep it to port in the conventional direction.

Light

A common characteristic is composite group flashing (2+1) in the color of the uppermost band.