When should you use your horn or whistle while boating?

Using your horn or whistle is crucial for safety, particularly in situations where visibility is poor. In low visibility conditions, such as fog, rain, or darkness, sound signals serve as an effective means of communication among vessels that may not be able to see each other clearly. The horn or whistle alerts other boaters to your presence, helping to prevent collisions and ensuring that all vessels are aware of their surroundings.

While it's also important to signal in crowded marinas or when passing near other boats, the primary purpose of sound signals is to mitigate risks associated with reduced visibility. Nighttime boating can present visibility challenges as well, but the emphasis is on conditions where visual cues are limited. Therefore, using your horn or whistle in poor visibility situations is essential for safe boating practices.