Question 346 Rules of the Road

The correct answer is C) If a passing agreement is reached by radiotelephone whistle signals are optional. This is correct because under the Inland Navigation Rules, if two vessels can communicate by radiotelephone and reach a passing agreement, the vessels are not required to exchange whistle signals. As long as the passing agreement is clearly communicated and understood, the whistle signals are optional, even if the vessels will pass within 1/2 mile of each other. The other options are incorrect because they either mandate whistle signals in all situations (B), or require whistle signals regardless of a passing agreement (A, D).