What is the sound frequency range that vessels of less than 20 meters need to achieve?

The correct answer is based on the requirement that vessels of less than 20 meters in length must operate within a specific sound frequency range to ensure their sound signals are effective and can be detected by other vessels. The appropriate frequency range for such vessels is 180-700 Hz. This range ensures that sound signals from smaller vessels can be heard clearly, increasing safety and communication in maritime environments.

This frequency range is vital because it is sufficiently low to produce sounds that can travel over significant distances in water, while also being high enough to minimize interference from ambient noise. Proper communication through sound signals is crucial, particularly for small vessels, as they may not be as visible on radar or from a distance compared to larger ships. Thus, adherence to this standard effectively enhances safety and promotes situational awareness among all vessels operating in close proximity.