Port Side – Starboard Colors for Ships and Buoys
Did you know why the port side is marked with a red light and the starboard side with a green one? It’s not just tradition, but also a practical safety measure for navigation!
By Pranala Digital Transmaritim
08 January 2025
Did you know that red and green lights are used to mark the port and starboard sides of a ship? This tradition dates back to when red glass lanterns were used to mark port entrances, while green glass, although rarer, was used for starboard. Over time, this evolved into the color system we use today.
MV. Sinar Jambi – Self Propelled Deck Container Carrier 265 TEUs (2011). Photo: Bumi Samudera Jaya
Port Side (Left)
The port side is marked with a red light. This helps identify the left side of the vessel when facing forward (toward the bow).
When heading upstream, port-hand buoys (used to mark the left side of the channel) are:
– Green
– Have odd numbers
– Can appear as pillars with flashing lights, can-shaped markers, or flat-topped spars.
Keep these buoys on your left side when moving upstream.
Starboard Side (Right)
The starboard side is marked with a green light, indicating the vessel’s right side.
Starboard-hand buoys, used to mark the right edge of the channel, are:
– Red
– Have even numbers
– Typically, conical or topped with a conical shape
Keep these buoys on your right side when heading upstream.
Fun Fact About Port Side and Starboard?
This system dates back to when ports used red glass lanterns to mark entrances. Green glass—rarer at the time—was used for starboard. Over time, this color-coding became standard in maritime navigation.
Why It Matters:
By using this system, vessels can navigate more safely and efficiently, reducing the risk of collision and confusion in busy or low-visibility waters.