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)**. Rule 32 defines a "prolonged blast" as a blast of from **four to six seconds** duration. This definition applies universally to both International and Inland waters that adopt COLREGs. --- ### Explanation of Incorrect Options: **A) about one second:** This duration defines a **short blast** (approximately one second) used in maneuvering signals (Rule 32 and Rule 34), not the prolonged blast used for fog signals (Rule 35). **B) two to four seconds:** This range is too short for the required prolonged blast duration (4–6 seconds). It falls between the definitions of a short blast and a prolonged blast. **D) eight to ten seconds:** This duration is significantly too long. COLREGs specify the upper limit for a prolonged blast as six seconds.