🔍 Key Concepts

• Rule 23 – Power-Driven Vessels Underway (International) in the Navigation Rules • Special provision for very small, slow power-driven vessels (under 7 m and not exceeding 7 knots) • Difference between full lighting requirements (masthead, sidelights, sternlight) and minimal alternative lighting allowed for small craft

💭 Think About

• Ask yourself: When the Rules talk about exceptions for very small, slow power-driven vessels, what type of light are they allowed to show instead of the full set of navigation lights? • Compare each choice to the idea of being visible all around the horizon versus only in a particular direction or only when another vessel is close. • Consider whether the Rule is talking about lights that must be shown all the time when underway at night, or lights shown only in response to another vessel’s approach.

✅ Before You Answer

• Verify in Rule 23 if vessels less than 7 meters and not exceeding 7 knots may show an alternative single light instead of the standard lights. • Check which answer choices describe a light that is visible through 360° and can be seen from any direction. • Confirm that the correct option describes a light that must be shown whenever underway at night or in restricted visibility, not only conditionally when another vessel is already near.