Unlighted, red and green, horizontally-banded buoys with the topmost band red are classified as what shape?

The classification of unlighted buoys that have horizontal red and green bands, with the topmost band being red, indicates they fall under the shape of conical buoys, commonly referred to as nun buoys. These buoys are designed to mark the starboard side of the channel when entering from the sea in the United States.

The conical shape helps to visually indicate the buoy's identity and purpose to mariners, and the red topmost band is a standard feature for nun buoys, distinguishing them from can buoys, which have an upright cylindrical shape and are painted with a green topmost band.

Therefore, recognizing the shape and color scheme is crucial for navigational awareness, and identifying these buoys correctly aids mariners in safe and effective navigation through channels, harbors, and along waterways.