Question 46 ONC01 - Master/Chief Mate Unlimited Tonnage

The Correct Answer is D Option D ("All of the above") is correct because the fog signal of **one prolonged blast followed by two short blasts** is mandated by Rule 35(c) and 35(d) of the International Regulations for Preventing Collisions at Sea (COLREGs) and the corresponding Inland Rules for specific categories of vessels that are either underway (but limited) or at anchor (but restricted). Specifically: * **Rule 35(c) (COLREGs/Inland):** Prescribes this signal for a **vessel not under command** (C), a **vessel restricted in its ability to maneuver** (C), a vessel constrained by its draft (COLREGs only), a fishing vessel, a sailing vessel (B), and a vessel engaged in towing or pushing (if manned). * **Rule 35(d) (COLREGs/Inland):** Prescribes this signal when a vessel restricted in its ability to maneuver is **at anchor** (A). (Note: This signal is sounded in addition to the anchor signal required by Rule 35(g)). Since Options A, B, and C all describe vessel categories that are required to sound the signal of one prolonged followed by two short blasts under Rule 35(c) or 35(d), "All of the above" is the necessary choice. --- ### Why the other options are technically incorrect as the sole answer: While A, B, and C are all vessels that *must* sound this signal, selecting any one of them individually would ignore the other correct scenarios provided in the remaining options. Since the prompt asks which vessel(s) is/are required to sound the signal, and A, B, and C are all correct examples, D must be the answer. * **A) A vessel restricted in its ability to maneuver, at anchor:** This vessel is required to sound the signal (Rule 35(d)). It cannot be the sole answer because the vessels in B and C also require the signal. * **B) A sailing vessel underway:** This vessel is required to sound the signal (Rule 35(c)). It cannot be the sole answer because the vessels in A and C also require the signal. * **C) A vessel not under command:** This vessel is required to sound the signal (Rule 35(c)). It cannot be the sole answer because the vessels in A and B also require the signal.