conical buoy

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun nautical a buoy in the shape of a cone, normally painted black, and numbered with odd numbers, used to show the starboard side of a channel; the port side is marked with a can buoy

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a buoy resembling a cone