Question 39

The Correct Answer is C 1. **Explanation for Option C ("four to six seconds"):** The duration of a *prolonged blast* is defined in the navigation rules (specifically Rule 32 of the International Regulations for Preventing Collision at Sea, or COLREGs, and parallel Inland Rules) as a blast lasting from **four to six seconds**. This specific duration is crucial for distinguishing a prolonged blast from a short blast (approximately one second) in restricted visibility (fog). The signal described in the question (a prolonged blast) is the one required for a power-driven vessel making way or underway but not making way in fog. 2. **Explanation for Incorrect Options:** * **A) about one second:** This is the definition of a **short blast**, not a prolonged blast. * **B) two to four seconds:** This duration falls outside the accepted range for either a short or a prolonged blast and is not a defined signal duration in the rules. * **D) eight to ten seconds:** This duration is too long for a prolonged blast (four to six seconds).