They are the Arizona Uniform State Waterway Marking System, and they alert you to danger and give directions and restrictions. It is unlawful to moor or fasten a watercraft to any regulatory marker or remove, obstruct or interfere with any regulatory marker. Regulatory markers are can-shaped buoys colored orange and white. The nature of the danger may be indicated, e.g. rocks, reefs, dams, construction, or snags. A diamond with a cross inside means no boats are allowed.
Circles mean caution or controlled area.
The nature of the restriction is indicated, e.g. speed limit, no wake, no ski, ski only. A square or rectangular shape indicates information, directions, distances, names of places, or other general information. A can-shaped buoy with alternate red and white vertical stripes means the watercraft should not pass between the buoy and the shore. Mooring buoys are white with a horizontal blue band halfway between the top of the buoy and the waterline. It will be can-shaped and may show a white odd number.