Aids to Navigation — Road Signs of the Waterway (Visual Buoyage)
<a href="//commons.wikimedia.org/wiki/United_States_Coast_Guard" title="United States Coast Guard">United States Coast Guard</a>
<a rel="nofollow" class="external free" href="http://www.uscgboating.org/safety/aton/buoyage.htm">http://www.uscgboating.org/safety/aton/buoyage.htm</a>