What does the continuous sounding of a fog-signalling apparatus signify?

The continuous sounding of a fog-signalling apparatus signifies that visibility is reduced due to fog. This is a precautionary measure that vessels use to alert others of their presence when visibility is low, ensuring safety on the water. The sound signals serve as warnings to nearby vessels, allowing them to take necessary precautions to avoid collision in conditions where visual navigation is compromised.

Using a fog-signalling device emphasizes the importance of maritime communication and safety protocols in adverse weather conditions. It is crucial for vessels to be able to convey their position and movements when visual contact is limited, thus maintaining a safe distance from each other while navigating through fog-affected areas.