Buoys

 The US Coast Guard utilizes a variety of navigational buoys.  They may be constructed of metal, plastic, or foam.  Regardless, they are deployed for the purpose of assisting in the navigation of vessels, indicating the location of channels and warning of hazards.  There are seven basic types of buoys.  A can buoy is cylindrical, used principally to mark the left or port side of a channel.  A nun buoy is conical, used principally to mark the right or starboard side of a channel.  A bell buoy is larger than a can or nun buoy.  It has a flat top surmounted by a framework into which a bell is fixed.  The motion of the sea causes the bell to ring.  A gong buoy is similar to a bell buoy, but has four gongs (each with a different tone), rather than a bell.  A whistle buoy is also similar in shape to a bell buoy, but has a whistle that is activated by the motion of the sea.  A lighted buoy has a light that is powered either by batteries or by solar cells.  A combination buoy contains both a light and either a bell, gong, or whistle.  Many larger buoys are also fitted with radar reflectors.  Most navigational buoys are painted either red or green (or a design combining the two colors).  Until 1980, the Coast Guard painted its buoys either red or black, but the black buoys were changed to green to make them more visible to mariners, particularly at night.  Red buoys mark the starboard side of the channel (Red Right Returning!).  Green buoys mark the port side of the channel.  Junction buoys have red and green horizontal bands.  If the topmost band is red, that means the preferred channel is to port.  If the topmost band is green, the preferred channel is to starboard.  Certain buoys, such as those marking anchorage areas, have no lateral significance.  Other buoys are not intended for navigational purposes.  These include weather buoys and buoys marking special activities, such as dredging or boating regattas.  Note: This is an abbreviated overview of the buoyage system used in most US coastal waters.  It does not address buoyage in the Intercoastal Waterway or on certain inland waters.