can buoy

Wiktionary

1. n. nautical a truncated conical buoy, normally painted red and white, and numbered with even numbers, used to show the port side of a channel; the starboard side is marked with a conical buoy

GNU Webster's 1913

1. n. a hollow buoy made of sheet or boiler iron, usually conical or pear-shaped.
2. See under buoy, n.

WordNet 3.0

1. n. a buoy with a round bottom and conical top