What types of shapes can buoys have?

Buoys are typically designed in various shapes to serve specific navigational and marking purposes, helping mariners identify navigational aids. The shapes mentioned in the correct choice encompass commonly used buoy designs, which include:

• Can buoys, which are cylindrical and used to mark the port side of a channel.

• Nun buoys, which are conical and indicate the starboard side of a channel.

• Pillar buoys, which are often larger and more stable for marking significant points or hazards.

• Spar buoys, which are tall, slender, and used in deeper waters where stability needs to be maintained, often marked by a floating shape at the top.

Each of these designs has been standardized for easier recognition and to facilitate safe navigation. The mention of a sphere also reflects a basic geometric shape that may describe floating buoys but is less common in standard navigation aids. This understanding is crucial for mariners as it aids in identifying the type of navigation aid encountered while on the water.