“A buoy is a floating device, which can take on many forms, whether anchored or free drifting. These devices go by many names: Buoy, Bouy, Bouey, Bhoy, Bhouy, Float, Bouee, Flotteur, Boei, Boj, Boja, Boya, Boje, Bojen, Boia, Boa, Poi, Poiju, Bauja, Dufl, Pelampung, Plude, Flyteboye, Plovec & Samandira.

In the group Buoyant, we collect images of buoys and the waterscapes they exist in. A single buoy floating alone on a vast body of water is a metaphor for our isolation; and shows loneliness.” — TPorter2006

Photos from Potatojunkie, vijayal, and Panorama Paul.
As suggested (and written) by TPorter2006 in FlickrCentral.