Junction Buoys & Markers
A bifurcation buoy is used to mark the point where a channel devises in to branches. You may pass this buoy on either side (port or starboard side) when moving upstream. It's coloured with red and green bands. The main or preferred channel is shown by the color of the top band.
Junction markers indicate the preferred channel at points where the waterway splits or branches off in another direction. If you are returning from sea and see a preferred channel marker that is red over green, to stay in the main channel you would consider the marker as if it were a red marker and keep it on your right. However, if your intended destination is the waterway branch consider the marker a green marker and leave to your port side.