A buoy's a floating device that can have many different purposes. It can be anchored (stationary) or allowed to drift. The word, of Old French or Middle Dutch origin,'s now most commonly (identical with boy, also as in buoyancy), although some orthoepists have traditionally prescribed the pronunciation /ˈbwɔɪ/. The pronunciation /ˈbuː.iː/, while chiefly American, more closely resembles the modern French bouée . Types Sea mark - aids pilotage by marking a mari… (More on Buoy)