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

The correct answer is rooted in the non-mandatory requirements for sound signaling devices on vessels. For vessels measuring less than 20 meters in length, the legislation specifies that the sound signals they produce, particularly for navigating and distress signaling, should typically fall within a frequency range of 180 to 700 Hz. This frequency range ensures that the sound signals are audible and can effectively transmit the intended message to nearby vessels, especially in less than optimal visibility conditions or in busy waterways where a vessel must signal its presence or intentions.

The chosen frequency range allows for sufficient penetration through ambient noise and ensures that the sound is distinct enough to be heard by other vessels. It aligns with guidelines intended to promote safety on the water by ensuring that all vessels, regardless of size, can communicate effectively when necessary.

Understanding the specified frequency ranges is crucial for safe navigation and for fulfilling the COLREGs obligations regarding signals to other vessels, especially in scenarios that might require issuing a distress signal.