🔍 Key Concepts

• Vessel not under command (NUC) definition in the Navigation Rules • Difference between red and white all-round lights for vessel status • Standard light patterns: restricted in ability to maneuver (RAM) vs not under command (NUC)

💭 Think About

• First, recall what situation makes a vessel "not under command" and how serious that condition is compared to normal power-driven status. • Think about which color is used to signal that a vessel cannot maneuver as required by the Rules, and how many such lights are shown. • Compare the light pattern for a vessel restricted in ability to maneuver with that for a vessel not under command—how do the colors and sequence differ?

✅ Before You Answer

• Verify in the Navigation Rules (Annex I and Part C – Lights and Shapes) the specific light configuration for a vessel not under command. • Confirm whether the lights must be all-round and in a vertical line where they can best be seen. • Double-check that you are not confusing the pattern for restricted in ability to maneuver (three lights) with not under command (a different pattern).