What are the three types of sound signaling devices required for a vessel over 100 meters?

The correct answer identifies the required sound signaling devices for vessels over 100 meters as a whistle, bell, and gong. According to the International Regulations for Preventing Collisions at Sea (COLREGs), vessels of this size must be equipped with these specific devices to ensure effective signaling in various maritime conditions.

The whistle is essential for communication between vessels, especially in situations of limited visibility or navigation challenges. It produces a loud sound that can be heard over considerable distances. The bell serves a similar purpose, primarily as a signal indicating the presence of the vessel and its maneuvers, particularly in dense fog or other obstructive conditions. Lastly, the gong is used in very large vessels to signal their presence and intentions, especially when they are at anchor or in restricted waters.

This combination of devices is mandated to enhance maritime safety by ensuring that vessels can communicate clearly and effectively to avoid collisions and navigate safely in busy or hazardous waterways. Other options may mention different devices, but they do not align with the specific requirements set forth in the COLREGs for vessels over 100 meters in length.