Question 53 ONC02 - Second Mate/Third Mate Unlimited Tonnage

The Correct Answer is B **Explanation for Option B (The load line mark):** The load line mark (often referred to as the Plimsoll Mark and associated lines) is legally mandated and indicates the maximum depth to which a vessel can be safely loaded and legally submerged under various conditions (e.g., seasonal zones, type of water like fresh or tropical sea water). The specific line that represents the maximum permissible draft in summer saltwater conditions is the main indicator of the vessel's legally maximum allowed submersion. These marks are strictly governed by the International Convention on Load Lines (ICLL) and directly define the legal limit for submersion. **Explanation for Incorrect Options:** **A) The Muster List ("Station Bill"):** The Muster List is a document detailing emergency procedures, crew duties, and assignments during emergencies (like fire or abandonment). It has no relation to the vessel's maximum permissible draft or submersion limits. **C) The tonnage mark:** The tonnage mark is a physical line placed on the side of the vessel, sometimes used to determine the vessel’s applicable gross tonnage for regulatory or charging purposes (e.g., port fees). While it is a mark on the hull, it does not dictate the maximum legal submersion limit; that function belongs solely to the load line marks. **D) The Net Tonnage Certificate:** The Net Tonnage Certificate specifies the volume capacity of the vessel available for cargo and passengers, used primarily for calculating port dues and other fees. It is a measurement of capacity, not an indicator of the physical limit for legal submersion.