Which sound signaling device must a vessel that is 100 meters or longer use?

A vessel that is 100 meters or longer is required to use a whistle as part of its sound signaling devices. According to the International Regulations for Preventing Collisions at Sea (COLREGs), vessels of this size must have a whistle capable of producing a sound signal. The whistle is essential for communication with other vessels, especially in restricted visibility or during maneuvers where clear sound signals can prevent collisions.

The whistle serves a critical role in maritime safety, allowing vessels to convey their presence, intentions, or operational status to others navigating nearby waters. The specifications for using a whistle are designed to ensure that the sound produced is effective in alerting other vessels, promoting safe navigation.

The other signaling devices, such as horns, sirens, or bells, are not specifically mandated for vessels over 100 meters in the same capacity as the whistle. Understanding the requirement for sound signaling helps in adhering to safety regulations and enhances overall situational awareness while navigating maritime environments.