🔍 Key Concepts
• Masthead lights vs all-round lights in the Navigation Rules (look at Rule 23 for power-driven vessels and Rules 24–26 for special vessels)
• Which vessel categories use all-round red/green/white lights instead of masthead lights when engaged in their special operation
• How the requirement for an after masthead light depends on vessel length (over 50 meters) and type/status
💭 Think About
• For each choice, ask: when this vessel is in the condition described (e.g., at anchor, trawling, not under command, fishing), does it normally display masthead lights at all?
• If it does not show masthead lights in that condition, can it be required to add an after masthead light when over 50 meters?
• Identify which type of vessel, when over 50 meters, is specifically required by the Rules to carry a second (after) masthead light abaft and higher than the forward one.
✅ Before You Answer
• Verify in the Rules which vessels replace masthead lights with all-round lights when engaged in special operations (NUC, fishing, trawling, etc.)
• Check which Rule explicitly says: when the vessel is over 50 m, it shall show a second masthead light abaft and higher than the forward one
• Confirm that a vessel at anchor does not show masthead lights, only anchor lights, so consider whether it could meet an 'after masthead light' requirement in that condition