Buoy: A metal or wooden floating object usually anchored or moored on a dangerous rock or shoal at the entrance of a harbor, or at the edge of a channel, as a guide to navigators. Mooring buoys are also used as anchorages to secure vessels in specified positions. Buoys are often named according to shape, as the can buoy, which is a metal cylinder; the nun buoy, which has the shape of a truncated cone; and the spar buoy, which is an upright post, or spar, anchored at one end. The bell buoy is surmounted by a bell that is sounded by the action of the waves; the gong buoy, similarly operated, produces several distinctive, bell-like tones; and the whistle or horn buoy is fitted with a device by which air, compressed by the action of the waves, is led to escape through a whistle. Lighted buoys are extremely important aids to navigation at night; they are battery powered and emit light signals of different color and duration.

Each nation has a buoyage system of shapes, colors, numbers, and markings to indicate dangers to navigation. In the United States buoyage system, red, even-numbered buoys mark the starboard (right-hand) side of a channel, when coming from seaward, and black odd-numbered buoys indicate the port (left-hand) side. Buoys with red and black horizontal stripes mark channel junctions and isolated dangers.

Buoys - safety markers of the water
  1. This is a controlled area.
  2. There is potential danger.
  3. Boats are restricted from this area.
  4. Informational buoy.
  5. You should navigate to the South or West.
  6. You should navigate to the North or East.
  7. You should not pass between Shore and Buoy.
  8. Indicates an Anchor Buoy.
  9. Always pass between green (Port side, odd-numbered) and its companion red (Starboard, even-numbered) buoy. Keep red buoys to right and green to left while cruising upstream, or Red-Right-Returning if coastal boating.
  10. Indicates Mid Channel.
  11. Navigate to Port (facing upstream).
  12. Indicates that there are diver(s) below;
    be sure to give them a wide berth.