Do you plan on boating along the U.S. coastline or the Inland Waterways? Understanding the aids to navigation will assist you in having a safe and hassle-free trip. Aids to navigation are the road signs of the waterways. Aids to navigation are the same type of information that drivers use daily. Drivers use street signs, stop signals, road barriers, detours and traffic lights. Aids to navigation are lighthouses, minor lights, day beacons, range lights, sound signals, or lighted/unlighted buoys. Each of these aids has a purpose and can keep you safe and out of harms ways. 

Green buoys or markers are squares in shape and marked with odd numbers. When you proceed inland make sure to keep the green markers on the port (left) side of your boat. 
Red Buoys or Markers are triangles in shape and marked with even numbers. When you proceed inland from an offshore excursion, always keep the red marker on the starboard (right) side. 
Information or regulatory markers are orange and white in color and come with various symbols. Each symbol has its own meaning. Triangle signs indicate danger, alerting you of a hazard. Circle symbols indicate areas with regulated operations, slow or idle speed. A diamond shape with a cross signals that boats are prohibited from the area. Marks with a square provide helpful information such as direction, distance and location. 
Mooring buoys are white with a blue horizontal band and are cylinder or sphere shaped. They could show a white reflector or display a white or yellow light. They are the only type of buoys where mooring is permitted.
Intracoastal Waterway Marks (ICW) run parallel to the Atlantic and Gulf coasts from Manasquan Inlet, New Jersey to the Mexican border. Aids to navigation that mark the ICW display unique yellow symbols to distinguish them from other aids. A yellow triangle should be kept on the starboard (right) side of the vessel. Yellow squares should be kept on the port (left) side of your vessel. A yellow horizontal band provides no lateral information, but simply identifies the ICW. 
These aids to navigation will keep you safe and hassle-free on your trip on the water. These navigation aids will help prevent you from colliding with other boats or running into shallow water. These Aids to Navigation will make sure you get from one location to the next in the most direct and safe way.