What color symbolizes danger and should be used to mark isolated danger?

The color marking isolated dangers within the IALA Maritime Buoyage System is specifically designated as black with one or more red horizontal bands. This combination serves as a clear visual signal to mariners, indicating that the area is hazardous and should be avoided. The black color signifies a specific type of danger, while the red bands are universally associated with warnings and danger, making it immediately recognizable that a threat is present.

Using this color scheme allows for effective communication of hazard warnings to sailors and boaters. The black base ensures differentiation from other types of buoys, while the red bands enhance visibility and signal caution. This is critical for safety at sea, as it helps mariners navigate around underwater obstructions or areas that are unsafe for passage.