🔍 Key Concepts
• Rule 30 – Anchored Vessels and Vessels Aground of the Navigation Rules
• Special lighting for vessels engaged in special operations (e.g., not under command, restricted in ability to maneuver, mine clearance, pilot vessels)
• Size-related exceptions to anchor light requirements for small vessels and those in special locations (such as close to shore or in a narrow channel)
💭 Think About
• First, ask yourself: Rule 30 is about anchor lights. Does it list any type of work (underwater, mine clearance, pilotage, survey) as a reason to omit anchor lights, or does it focus on size and location?
• Think about which of the listed vessel types already have their own distinctive lights when underway or engaged in their work. Would those special lights normally replace anchor lights, or are anchor lights still required when they are actually anchored?
• Review which, if any, vessels in the Rules are explicitly exempted from showing anchor lights when anchored, and check whether that exemption is tied to what they are doing or to their length/position.
✅ Before You Answer
• Look up Rule 30 and confirm what it actually says about when an anchored vessel must or need not show anchor lights.
• Check whether any of the specific operation types listed in the answers (underwater, mine clearance, pilotage, survey) are named in Rule 30 as exceptions to anchor lights.
• Verify whether the only listed exemptions for anchor lights are based on vessel length and where the vessel is anchored (e.g., in a narrow channel, fairway, or close to shore) rather than on the vessel’s special function.