Which buoy may be odd numbered?

The unlighted can buoy is appropriately designated as odd numbered in the U.S. Aids to Navigation System. This numbering scheme is significant as it aids in the identification and navigation around the buoy. Odd-numbered buoys typically indicate a specific side of the channel, with can buoys representing the port side as vessels approach from the sea.

In contrast, spherical buoys are not classified by numbers; they serve a different purpose, often indicating hazards or specific locations rather than marking channels. Red buoys, which are used primarily for marking the starboard side of a channel when returning from the sea, are also even numbered according to the system. Yellow buoys are designated for special purposes and do not fall into the odd/even numbering classification typically applied to can and nun buoys. Therefore, the unlighted can buoy's designation as odd numbered is consistent with navigational standards that help mariners safely navigate waterways.