Spar buoys, also called pillars, are cylindrical and usually made from plastic, metal, fiberglass, or large logs.
They are usually lighted and come in standard colors corresponding to various hazard levels.
Can buoys have a wide, cylindrical upper portion that resembles a can.
They are either painted green or with red and green horizontal stripes.
They are unlighted and usually marked with odd numbers.
Nun buoys, also called red nuns, have a cone-shaped upper half and a rounded tip.
They are also unlighted and are painted red or with red and green bands.
They may be tapered throughout or have a cylindrical base for stability.
Spherical buoys are round and unlighted.
They painted with white and red vertical stripes.
They are used to indicate the middle of a channel.