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What Color is on the Starboard Side of a Boat? (Red & Green)

Fact checked by William Hart

what color is on the starboard side of a boat

When boating during nighttime, you will notice other vessels displaying an array of lights. Besides signaling the presence of the vehicle, these lights help you tell which part of that vessel is facing you—bow, stern, portside, or starboard side.

So, what color is on the starboard side of a boat? The answer is green. When you see a green sidelight from afar, that vessel is approaching you from its starboard side. You can keep your course and maintain your speed; that vessel will give way.

Table of Contents

What Color is Displayed on the Starboard Side of a Boat?


1. White, red, or green

Just like your car’s headlights, boat lights are essential when visibility is reduced (e.g., nighttime, fog, or rain.) They communicate a vessel’s presence, size, and direction, allowing other boats in the area to navigate the water without collisions.


As you cruise in the nighttime, you shall notice three different lighting colors on each vessel: white, red, and green. What do they mean? Which color is on the starboard side of a boat?

2. Meaning of each color

There are three mandatory lights on each ship: two sidelights (one for the port side and one for the starboard side) and one sternlight, each carrying a different color. The color scheme is strictly regulated by marine laws, and some states may have additional requirements.

The meanings of these running lights are as follows:

  • The starboard navigation light is green. The starboard side of boat is the right side of the operator when he or she looks toward the bow.
  • The portside light color is red. The port side is the left side of the operator when he or she looks toward the bow.
  • The boat’s sternlight is white and located in the ship’s rear section.

On power vessels, you will notice a white light shining at the bow, spread to both sides, and located above the red and green colors for port and starboard. It is called a masthead light.

On smaller motor vessels, manufacturers often replace the masthead light and stern light with an all-around white light that can be seen from all directions. When anchoring a boat at night or during low visibility, the owner needs to leave the all-around white light on.

Besides colors, boat lights must meet illumination requirements. White bow light colors, for example, must be bright enough to be spotted from 2 miles away.

3. Interpreting the lights on other vessels


Learning the starboard and port colors is simple. But when you spot a light approaching your vessel, what should you do? Should you maneuver to give way or maintain your course?

According to marine navigation rules, the vessel having its starboard side against the other must yield. So, here is how to navigate the situation:

  • When you approach a vessel from the left and that vessel has a green light (starboard light), you can keep your course and maintain your speed, and that vessel will give way.
  • When you approach a vessel from the right and that vessel has a red light (portside light), you should slow down and maneuver to give way to that vessel.

4. Responsibility of boat owners

Navigation lights are essential in ensuring safety at night. They allow you to interpret the direction of other vessels and approach them safely.

As the owner of your boat, you are responsible for:

  • Understanding the meaning of navigation light colors
  • Displaying the correct light color scheme on your vessel and ensuring the lights work properly
  • Ensuring that the locations and angles of the lights meet the requirements
  • Turning on the sternlight, sidelights, and all-around white light of the ship from sunset to sunrise and during low-visibility conditions

Additionally, you should build up your experience before operating at night for the first time. Boating in low visibility requires a different skill set. You must maintain a sharp watch for navigational aids and other vessels, keep a safe speed, and stay calm under dangerous situations.

Note: When buying a second-hand boat, you must check whether its lights meet the law requirements, especially if its lighting system has been altered by the previous owner. You might face heavy fines and other penalties when launching boats with inappropriate lights.



Why are starboard right and port left?

When facing forward, the starboard side is the right while the port side is the left. Boaters use these terms instead of left and right because they remain unchanged regardless of the speaker’s standing position, allowing quick and clear communication.

The origin of port and starboard side dates back to the ancient time when boats were operated by oars.

Since most oarsmen were right-handed, they preferred their steering oars to be on their right side. Most ancient boats were constructed like so.

Soon, this side adopted the name “steering side”, but in old English, it was “stéor bord.” With time, the words evolved into “starboard side” in modern English that we use today.

The other side was free of oars, so boaters approached ports from that side for goods loading, which brought it the name “port side.”

Why are starboard side green and port red?

In the old time, the steering oars were placed on the starboard side. Thus, oarsmen’s vision remains on the right side while operating the boat.

Because of that, red coloring was put on the left to signify danger. This tradition is kept until today, and that is why manufacturers adopt red lights for the port side of a vessel.

How to remember port and starboard?

Port and starboard sides can get confusing at times. The trick is to count the letters of the word. Port has four letters in it while left also has four letters. So, when you think port side, think left.

What does blue light on a boat mean?

Besides red, green, and white, you might spot blue lighting on boats. A vessel carrying a blue light is one belonging to the authority. When seeing a blue light vessel, you might want to maintain a sharp watch and ensure that you operate your boat properly.

What does a yellow light on a boat mean?

Cargo ships turn on a yellow light when they tow a barge. When you see this light, make sure to stay out of their way, especially when you are in a shipping lane.

What is the green red port starboard?

You can tell the port side from the starboard side by the color of their lighting. Green light signifies the starboard side while red light indicates the port side of a vessel.


What color is on the starboard side of a boat? The short answer is green. When you see a vessel approaching from its green side, maintain your course. But when you see a vessel approaching from its red (port) side, maneuver to give way to that vessel.

In addition to the lighting systems of boats, you need to learn about navigational aids, buoys, and channel markers before standing behind the wheel for the first time. So, don’t hesitate to browse our website for more information. See you around!

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