Which power-driven vessel is NOT required to carry a light in the position of the after masthead light?

• A. A vessel under 20 meters
• B. A vessel of 45 meters in length trolling
• C. A vessel of 70 meters
• D. A sailing vessel

Answer: (B)

The rule that this question tests is about when a second white light at the after masthead is required on power‑driven vessels underway. That after-masthead light is not needed on smaller vessels; it’s reserved for longer craft. In practice, the requirement applies to vessels at or above a certain length (roughly 50 meters in many regulations). A power-driven vessel that is shorter than that threshold isn’t obligated to display a light in the after‑masthead position, even if it’s engaged in fishing like trolling. Therefore, a 45‑meter trolling vessel is not required to carry the after‑masthead light. The other options would either exceed the length threshold (where the after‑masthead light would be required) or involve a vessel that isn’t power‑driven, which falls outside the situation described.