If a vessel of special construction cannot comply with the Rules for lights, what should it do?

• A. Ignore the rules.
• B. Display standard lights anyway.
• C. Cease navigation.
• D. Comply as closely as possible, as determined by your government.

Answer: (D)

When a vessel of special construction cannot meet the standard light configuration, it must adopt the closest possible alternative that conveys the same signaling intent, but this must be determined or approved by the vessel’s government (the flag state). The lights are there to communicate a vessel’s status and maneuvering that helps others avoid collisions; if the design prevents standard lights, the authorities authorize an equivalent scheme that preserves that signaling. Ignoring the rules, using standard lights anyway, or stopping navigation are not appropriate responses. The approved alternative ensures other vessels still understand the situation safely.