Question 39

The Correct Answer is C 1. **Why option C ("four to six seconds") is correct:** The duration of a prolonged blast is defined in the maritime rules of the road (COLREGs, Annex III, Rule 3(b)) as a blast of from four to six seconds duration. This definition applies universally under both the International and Inland Rules for whistle signals used during restricted visibility (fog), specifically for the signal (one prolonged blast every two minutes) given by a power-driven vessel. 2. **Why the other options are incorrect:** * **A) about one second:** This duration defines a **short blast**, not a prolonged blast. A short blast is used for maneuvering signals (e.g., "I am altering my course to starboard"). * **B) two to four seconds:** This range is too short for a standard prolonged blast (which must reach at least four seconds) and too long for a short blast. * **D) eight to ten seconds:** This duration is significantly longer than the defined maximum of six seconds for a prolonged blast and is not specified for any standard whistle signal in the COLREGs.