Question 112 Rules of the Road

The correct answer is D) they are passing within half a mile of each other. The Inland Navigation Rules, which govern the operation of vessels on U.S. inland waterways, require that power-driven vessels in sight of one another shall exchange whistle signals when passing within half a mile of each other. This is to ensure clear communication between the vessels and promote safe passage. The other answer choices are incorrect because: A) exchanging whistle signals is not dependent on doubt about the passing arrangement, B) whistle signals are required regardless of whether course changes are necessary, and C) whistle signals are required even if passing agreements have been made by radio.