🔍 Key Concepts

• Working lights and how they are defined in the Navigation Rules (in relation to deck illumination) • The lighting requirements for a vessel over 100 meters in length at anchor • Whether vessels not under command or constrained by their draft have specific rules about illuminating decks

💭 Think About

• Ask yourself: which of these vessels is specifically required by the rules to have its decks illuminated, not just navigation lights? • Consider when deck illumination is needed for visibility and safety while the vessel is stationary versus when it is underway. • Review the difference between navigation lights (red/green/white) and working/deck lights in the Rules—who is told to use which and when?

✅ Before You Answer

• Verify in the Navigation Rules which vessel type has an explicit requirement that working lights shall be used to illuminate the decks. • Check whether vessels not under command or constrained by their draft have any mention of required deck illumination (beyond their standard shapes and lights). • Confirm if the rule about deck illumination applies only to a particular size and status (e.g., length over a certain number of meters and at anchor).