What is required on federally-controlled waters for boats less than 39.4 feet long?

On federally-controlled waters, boats that are less than 39.4 feet long are required to carry a whistle as part of their safety equipment. A whistle can be used as a sound signal device to communicate with other vessels in various situations, such as during reduced visibility or to signal intentions while navigating. This is crucial to ensure safety on the water, as sound signals are vital for avoiding collisions and alerting other boaters of your presence or plans.

While life jackets for all passengers is a critical safety requirement, the specific focus of the question is on federally-controlled waters where a whistle is explicitly mandated. Similarly, although visual distress signals are important for communicating emergencies, they are not specifically required for all boats under this length. Therefore, the requirement for a whistle serves a key role in promoting safe boating practices on such waters.