Question 46 ONC02 - Second Mate/Third Mate Unlimited Tonnage

The Correct Answer is D. **Explanation of why option D ("All of the above") is correct:** The fog signal of "one prolonged blast followed by two short blasts" is mandated by Rule 35(c) (International and Inland) of the COLREGs (Convention on the International Regulations for Preventing Collisions at Sea, 1972) for specific vessels that are **underway but unable to maneuver normally**, or **at anchor/aground in specific circumstances**. This signal is required for the following categories of vessels, which include all vessels listed in options A, B, and C: 1. A vessel restricted in its ability to maneuver (RAM) 2. A vessel constrained by its draft (International only, but uses the same signal) 3. A vessel not under command (NUC) 4. A fishing vessel (when gear is down) 5. A towing vessel (when towing) 6. A sailing vessel 7. A vessel engaged in minesweeping Since all vessels listed in A, B, and C fall under the categories required to give this specific fog signal (Rule 35(c)), option D is correct. **Brief explanation of why each of the other options is incorrect:** * **A) A vessel restricted in its ability to maneuver, at anchor:** This option is partially misleading. A vessel restricted in its ability to maneuver (RAM) **underway** is required to sound this signal (Rule 35(c)). However, a vessel **at anchor** is required to sound the distinct anchor signal (rapid ringing of the bell for 5 seconds every minute, Rule 35(g)). Therefore, Option A alone is not the complete answer, as it includes a vessel that would typically use a different signal (if strictly "at anchor"). Since the question asks which vessels are **required** to use the signal, and vessels listed in B and C are *also* required to use it, selecting A alone is insufficient. * **B) A sailing vessel underway:** A sailing vessel underway is explicitly required to sound the signal of one prolonged followed by two short blasts (Rule 35(c)). However, selecting B alone is insufficient because vessels in categories A and C are also required to use this signal. * **C) A vessel not under command:** A vessel not under command (NUC) is explicitly required to sound the signal of one prolonged followed by two short blasts (Rule 35(c)). However, selecting C alone is insufficient because vessels in categories A and B are also required to use this signal.