What type of buoy is a conical, red buoy bearing an even number?

The correct choice for a conical, red buoy bearing an even number is known as a Nun buoy. This type of buoy helps to indicate the edges of channels, guiding vessels safely through waterways. Nun buoys are typically found on the right side of a channel when entering from the open sea or from a specific body of water. The red color signifies that it is a buoy marking the starboard side of the waterway.

In addition, the conical shape of the Nun buoy is distinctive and aids in identifying it among other types of buoys. The presence of even numbers on these buoys corresponds with the IALA (International Association of Lighthouse Authorities) buoyage system, which further reinforces their role in navigation.

Other options like the Spar buoy and Warning buoy serve different purposes in boating navigation and safety. A Spar buoy is generally used for marking locations or hazards, while a Warning buoy alerts boaters to specific dangers. The Can buoy, which is usually cylindrical and colored green, marks the port side of a channel, contrasting with the Nun buoy's role and markings. Each type of buoy has its unique features and functions, underscoring the importance of recognizing each to ensure safe navigation.