What must vessels 100 METERS OR MORE in length have for sound signaling?

Vessels that are 100 meters or more in length are required to have specific sound signaling devices as outlined in the International Regulations for Preventing Collisions at Sea (COLREGs). For these larger vessels, the regulations mandate that they must have a bell, a whistle, and a gong.

The bell is used in restricted visibility while operating at anchor, the whistle is utilized for signaling in various navigation situations, and the gong acts as an additional sound signal to further enhance communication, especially in poor visibility. Having all three devices ensures that the vessel can effectively signal its presence and intentions in a variety of maritime scenarios, thereby enhancing safety on the water.

The other options do not fulfill the complete requirement laid out in the regulations. Only having a whistle, for instance, would not meet the safety standards expected for a vessel of this size, as it lacks the necessary auditory signaling capabilities that the bell and gong provide. Therefore, the comprehensive requirement of a bell, whistle, and gong ensures optimal compliance with maritime safety standards for large vessels.