What is the audibility frequency range for vessels less than 20 meters?

The audibility frequency range for vessels less than 20 meters is defined within the range of 180-700 Hz. This range is specifically set to ensure that vessels of this size can effectively communicate their presence and signals in varying environmental conditions, especially in situations where visibility may be compromised.

The chosen frequency range is crucial because it allows for optimal sound propagation in marine environments. Frequencies lower than this range may not be effective in cutting through ambient noise caused by waves, wind, or other vessels, while frequencies that are too high may not be audible over such conditions.

This frequency range is established in international maritime regulations to enhance the safety of smaller vessels that may not have the same level of sound signaling equipment or capabilities as larger vessels. By adhering to this specified range, smaller vessels can ensure that they are heard by others, thus contributing to overall navigational safety and reducing the risk of collisions.