Which sound signal from a ship's horn indicates a specific maneuver?

The correct choice highlights that different ship maneuvers are indicated by varying lengths of sound signals from a ship's horn, making it a fundamental aspect of maritime communication. In maritime practice, specific sound signals are universally recognized to convey information regarding a vessel's intentions or maneuvers, ensuring safety and awareness among nearby vessels.

For example, a prolonged blast may signify that a vessel is leaving its berth, while two short blasts may indicate a right turn or an overtaking action. By utilizing variations in the length and pattern of sound blasts, mariners can effectively communicate their next moves without visual signals, which is particularly useful in conditions of poor visibility.

This system of sound signals enhances navigational safety, ensuring all nearby vessels understand each other's intentions and can respond appropriately, thus minimizing the risk of collisions or misunderstandings at sea. Hence, the choice that focuses on the relationship between different sound signals and their corresponding maneuvers is correct as it captures the essence of maritime communication protocols.