BOATsmart! USA Knowledge Base

Module 05 - Navigating the Waterways

The Four Main Types of Lateral Buoys

Green Navigation Aids:

These green markers identify the edge of the channel on the port (left) side of the boat as you enter the waterway from the open sea or when heading upstream. They are identified by a letter and an odd number. They’re always flat on the top (‘cans’) and will sometimes exhibit a flashing light.

Red Navigation Aids:

These red markers indicate the starboard (right) side of a channel and must be kept on the right side of your boat when heading upstream. Red markers are identifiable by letter and an even-digit number. They are always pointed at the top (‘nuns’) and will sometimes exhibit a flashing light.

Red and Green Navigation Aids:

These red and green markers, also known as ‘Junction Buoys’, indicate the intersection of two different channels. The colored stripe on top indicates the primary or preferred channel for navigation.
Port-Junction Buoys are green on top with a red horizontal band in the middle. They must be kept on the port (left) side of your boat when you’re heading upstream.
Starboard-Junction Buoys are red on top and have a green horizontal band in the middle. They must always be kept on the starboard (right) side of your boat when you’re heading upstream.

Daymarks:

Also known as ‘daybeacons’, these are signs (red triangles and green squares) that are posted on structures that are on land or in the water and are typically used as channel or hazard markers. The same color rules apply to daymarks as to buoys: green Daymarks must always be kept on the port (left) side of your boat and red Daymarks must always be kept on the starboard (right) side of your boat. Daymarks will sometimes have a flashing light but they’re primarily intended for daytime use.

Remember that ‘opposites attract’. Red and green belong together when you’re traveling upstream! The port sidelight on your boat (red) will always match up with the green buoys and markers. This means that you should always have a green buoy on your left. This ‘opposites attract’ rule goes for matching the starboard sidelight (green) with the red buoys and markers. You should always have a red buoy on your right!