Buoys that mark isolated dangers are painted with alternating ________.

Buoys that mark isolated dangers are indeed painted with alternating red and black bands. This color scheme is specifically designed to indicate to mariners the presence of a hazard, such as wrecks or rocks, that must be avoided. The use of these colors is standardized by the United States Coast Guard to ensure consistency and recognizability among navigational aids.

By painting these buoys in striking red and black bands, it provides a clear visual cue that distinguishes them from other types of buoys, enhancing safety at sea. This color combination helps mariners quickly identify the type and purpose of the buoy, promoting better navigational practices and reducing the risk of accidents.

Other options provided represent different types of navigation aids or features. For instance, green and white bands are not used for isolated dangers; they may be associated with other navigational purposes, such as lateral marks. Understanding the significance of these specific color combinations is crucial for effective navigation.