What signaling devices must a vessel between 20 to 100 meters have?

A vessel measuring between 20 to 100 meters in length is required to carry specific signaling devices as per the regulations established in the COLREGs. The correct answer indicates that such a vessel must have a whistle and a bell as its sound signaling devices.

The whistle serves as an essential instrument for signaling in various maritime situations, particularly for communication with other vessels to prevent collisions. It is typically used to produce sound signals that communicate a vessel’s actions or intentions to nearby vessels.

The bell, in addition to the whistle, plays a crucial role in indicating the presence of the vessel, especially when at anchor. The requirement for having both devices ensures that the vessel can effectively signal its position and maneuvers, which is vital for safe navigation, particularly in areas where visibility may be compromised.

In contrast, the other options provided either suggest combinations of devices that exceed the necessary requirements or include devices that are not mandated for vessels of this size under the COLREGs. This clarifies the requirements set forth to ensure clear maritime communication while adhering to international safety standards.