🔍 Key Concepts
• Rule 23 – Power-driven vessels underway (what lights are shown when seen from right ahead)
• Rule 26 – Fishing vessels (color and arrangement of lights for trawling vs other fishing)
• Rule 27 – Vessels restricted in their ability to maneuver (including dredging)
💭 Think About
• Look first at the colors and vertical arrangement of the two upper lights: are they the special red/green combinations used for fishing or restricted vessels, or are they ordinary white lights?
• Ask yourself: if you are directly ahead of a large power-driven vessel at night, which lights would you see at once, and how would they be arranged?
• Compare what additional lights would be required if the vessel were fishing, trawling, or dredging – do you see any red-over-white, green-over-white, or red-white-red combinations in the illustration?
✅ Before You Answer
• Verify whether any of the upper lights are red or green; special operations (fishing, trawling, dredging) all use colored all-round lights in specific pairs.
• Check if the pattern matches green over white (trawling), red over white (fishing other than trawling), or red–white–red (restricted/dredging); if it does not, eliminate those options.
• Confirm that you are seeing both sidelights (red and green) at the same time, which tells you about your relative position to the vessel.