Question 38 ONC03 - Master LT 500-1600 GRT

The Correct Answer is A. **Why option A ("I am altering course to port") is correct:** The question specifies that the situation is "INTERNATIONAL ONLY." The rules governing whistle signals are found in the International Regulations for Preventing Collisions at Sea (COLREGs), specifically Rule 34(a). Rule 34(a) states, in part, that when power-driven vessels are in sight of one another, a signal of: * **One short blast** means: "I am altering my course to starboard." * **Two short blasts** means: "I am altering my course to port." * **Three short blasts** means: "I am operating astern propulsion." Therefore, a two-blast whistle signal means the vessel is actively altering its course to port. **Why the other options are incorrect:** * **B) "I desire to pass starboard to starboard":** This option suggests a desire or proposal for a specific passing arrangement. While two short blasts usually precede a starboard-to-starboard pass (because the vessel is turning left/port), the signal itself, under international rules, describes the *action* being taken (altering course to port), not a proposal for a passing arrangement. (Note: Under Inland Rules, this signal has a different meaning—a proposal—but the question specifically asks for INTERNATIONAL ONLY.) * **C) "I desire to pass port-to-port":** This arrangement is associated with a vessel turning to starboard, which is signaled by one short blast ("I am altering course to starboard"). * **D) "I intend to alter course to port":** In COLREGs Rule 34(a), the language used ("I am altering my course...") describes the action as immediate and ongoing, not merely an intention or desire for a future maneuver. The signal confirms that the vessel is actively making the turn.