INLAND ONLY Two vessels in a crossing situation have reached agreement by radiotelephone. In this situation, which statement is TRUE concerning whistle signals?

Correct Answer: Option C — not required, but may be sounded

33 CFR 83.34(h) (Inland Rule 34) states that vessels reaching an agreement by radiotelephone are not obliged to sound the whistle signals prescribed in Rule 34(a), but they may do so if they choose. This provides flexibility for bridge-to-bridge communication while maintaining the option for traditional sound signals.