For vessels 20 METERS OR MORE in length, what is required?

Vessels that are 20 meters or more in length are required to be equipped with a whistle and a bell to comply with sound signaling regulations as outlined in the International Regulations for Preventing Collisions at Sea (COLREGs). The whistle is used to signal intentions or actions, especially in situations where visibility is limited or during maneuvers in congested waters. The bell serves a specific function as well, particularly for indicating the vessel's presence during anchoring or when navigating in reduced visibility conditions.

The requirement for both a whistle and a bell ensures that the vessel can communicate adequately and effectively with other vessels nearby, enhancing navigational safety. While other sound signal devices such as horns and gongs might be used in different contexts or for vessels of different sizes, the combination of whistle and bell is specifically mandated for vessels of this length to meet maritime safety standards.