Question 39

The Correct Answer is C The duration of each prolonged blast on whistle signals used by a power-driven vessel in fog, whether making way or underway but not making way, is defined by the **International Regulations for Preventing Collisions at Sea (COLREGs)**, Annex III, Section 1(a). **Explanation for C ("four to six seconds") being correct:** COLREGs defines a "prolonged blast" as a blast lasting from four to six seconds (4 to 6 seconds). This definition applies universally to both International (Rule 35) and Inland Rules where prolonged blasts are specified for restricted visibility signals (e.g., a vessel making way, a vessel underway but stopped, etc.). **Explanation of why other options are incorrect:** * **A) about one second:** This duration defines a **short blast**, not a prolonged blast. A short blast is used primarily for maneuvering and warning signals in sight of another vessel (COLREGs Rule 34). * **B) two to four seconds:** This range is too short. While it is close to the lower limit, the official definition mandates the blast be at least four seconds long. * **D) eight to ten seconds:** This duration is too long. While very long blasts might sometimes be used informally as warnings, the official definition of a prolonged blast is capped at six seconds for regulatory compliance.