Lights & Markers

Navigation lights and ATON identification. IALA Region B (US waters). Tap for details.

What Do I See At Night?

Red + Green = vessel coming toward you

Red only = vessel crossing, you see its port side, it has right of way

Green only = vessel crossing, you see its starboard, you have right of way

White only (single) = stern view (overtaking) or vessel at anchor

White + Red + Green = power vessel bow-on (head-on situation)

Red over Red = not under command - KEEP CLEAR

Red-White-Red = restricted in ability to maneuver

Based on USCG Navigation Rules (COLREGS) and IALA Maritime Buoyage System Region B. This is a simplified reference. Always carry the full Navigation Rules book aboard.