Dictionary of Ichthyology  

buoy = a float moored to the bottom that marks a navigational channel, a position such as a shoal, a wreck or a net or trap. Also used to show the position of an anchor for attaching a boat and then called a mooring buoy. Pronounced "boy" in English and "boo-ee" in American. Variously coloured and shaped, of widely different sizes, and may have a whistle, bell or gong.
Early 20th century buoy used to mark the main shipping channel on the St. Lawrence River, Quebec City. Photograph by Brian W. Coad.....more

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