Question 47 ONC02 - Second Mate/Third Mate Unlimited Tonnage

The Correct Answer is D **Explanation for Option D (Correct Answer):** The question asks for the fog signal required for a **manned vessel being towed** when operating under the International Regulations for Preventing Collisions at Sea (COLREGs), which apply to both International and Inland waters (unless superseded by specific inland rules, but the COLREG standard is the default and correct answer here). Rule 35(e) of COLREGs specifies the signal for a vessel being towed: > "A vessel being towed, if the manned vessel, or the last vessel, of a tow is manned, may at intervals of not more than 2 minutes sound **one prolonged blast followed by three short blasts**." Therefore, this signal specifically identifies the vessel as being part of a tow and is required at night and in restricted visibility. **Explanation of Incorrect Options:** * **A) One prolonged followed by two short blasts:** This is the required fog signal for a **sailing vessel**, a **power-driven vessel when under way but stopped and making no way through the water**, a **vessel restricted in her ability to maneuver** (when underway), and a **vessel constrained by her draft**. It is not the signal for a vessel being towed. * **B) Two prolonged blasts:** This is the fog signal required for a **vessel at anchor** (as a general warning, usually sounded immediately after the rapid ringing of the bell). It is also the signal used by a pilot vessel when on pilotage duty (in addition to the vessel's primary signal). It is not the signal for a vessel being towed. * **C) One prolonged followed by one short blast:** This signal is used by a **power-driven vessel under way making way through the water**. It is the standard signal for a typical vessel proceeding in fog. It is not the signal for a vessel being towed.