they are cylindrical in shape
Like cans, they are cylindrical.
In the United States, red buoys have red lights, and are even numbered. If the are unlit they are in the shape of a semi-cone and are called "nun" buoys. The day markers are red triangles.
Shape, colour and lighting
Some red buoys are known as "nun" buoys.(Ref: SB-4)some red buoys are known as nun buoys
Mooring buoys
Some red buoys are known as "nun" buoys.(Ref: SB-4)some red buoys are known as nun buoys
Mid channel buoys
Regulatory Buoys.
Yellow buoys are weather stations.
Anchor or mooring buoys do not have lights
Yellow buoys are weather stations.