INTERNATIONAL ONLY Vessel "A" is overtaking vessel "B" on open waters as shown in illustration D017RR below and will pass without changing course. What signal should vessel "A" sound?

Correct Answer: Option D — No whistle signal should be sounded

Rule 34(a) states that whistle signals are used to indicate an alteration of course. If an overtaking vessel can pass without changing course, no whistle signal is required under International Rules. Signals are only sounded when a vessel is actively maneuvering to alter her course to starboard or port.