🔍 Key Concepts

• Rule 23 – Power-driven vessels underway (International Rules) • Special provisions for small power-driven vessels under 7 meters and under 7 knots • Difference between required navigation lights and optional / alternative lights for very small, slow vessels

💭 Think About

• Look at what lights a normal power-driven vessel underway must carry, then ask: what relaxations are allowed for very small, slow boats? • Which of the listed options actually gives other vessels enough information to avoid collision at night? Consider visibility and color of the light(s). • For a vessel this small and slow, does the rule still require sidelights and a masthead light, or does it permit a single simpler light arrangement instead?

✅ Before You Answer

• Verify the exact wording in Rule 23(d) (or equivalent subsection) that addresses vessels under 7 meters whose maximum speed does not exceed 7 knots. • Check which of the answer choices match the colors and sectors mentioned in that small-vessel exception (white vs red/green; all-round vs sidelights). • Confirm that the option you choose is described as permitted “in lieu of” the standard lights for a power-driven vessel, not a light used for some other purpose (like towing or special operations).