A description on a nautical chart indicating a RACON signifies what?

A RACON is a specific type of navigational aid that serves as a radar transponder beacon. When a vessel's radar system detects a RACON, it receives a distinctive response that helps to identify the beacon's location and reinforces the vessel's situational awareness. This ability to enhance radar navigation is crucial for vessels operating in challenging environments, such as busy shipping lanes or areas with limited visibility. The unique signal transmitted by a RACON typically indicates its geographic location, aiding mariners in safe navigation.

In contrast, the other choices represent different types of navigational aids or signals that do not fall under the definition of a RACON. Sound signal buoys generate auditory signals for navigation, lighted navigational aids are used primarily for visual references at night or in reduced visibility, and danger signals are warnings about obstacles or hazards in the water. Each of these serves important roles in navigation, but they do not perform the specific function of a radar transponder beacon like a RACON does.