By no means all are. Some are spherical, some are hemispherical, and some shaped like an inverted teardrop.
they are cylindrical in shape
Like cans, they are cylindrical.
Like cans, they are cylindrical.
They are cylindrical
A can buoy is a floating cylindrical object in the water. They are red in British waters and green or black in US waters.
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
Yellow buoys are weather stations.
Regulatory Buoys.
Yellow buoys are weather stations.