The Navigation Rules are much like the rules of the road on the highway. They establish a consistent way to navigate safely and avoid collisions when two boats are crossing paths, are on course to meet head-on, or when one boat wishes to overtake another.
The U.S. Aids to Navigation System is a system maintained by the U.S. Coast Guard, consisting of visual, audible, and electronic signals which are designed to assist the prudent mariner in the process of navigation. The aids to navigation system is not intended to identify every shoal or obstruction to navigation which exists in the navigable waters of the United States, but rather provides for reasonable marking of marine features as resources permit.
Aids to Navigation can provide a boater with information similar to that which drivers get from street signs, stop signals, road barriers, detours, and traffic lights. Download your copy of the Aids to Navigation System booklet to learn about navigation rules, essential markers, navigational maps, and more!
Source: uscgboating.org