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

The correct designation for unlighted, red and green, horizontally-banded buoys with the topmost band red is conical nun buoys. These buoys are specifically identified by their color and banding pattern, which serves a crucial purpose in navigation by indicating safe passage for vessels. The red topmost band signifies that the buoy is marking a navigational hazard or indicating a channel's side that must be kept to the vessel's starboard side when returning from sea. This system of marking is standardized, making it essential for operators to recognize these specific characteristics for safe navigation.

Understanding the conical shape and its coloration helps operators interpret the buoy's meaning correctly. Alternative buoy shapes and color markings serve different navigational purposes, emphasizing the importance of identification. In this case, the specific design and color coding of the conical nun buoys serve to distinguish them from other types, such as cylindrical can buoys, which have different identifying features.