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Why Do Boats Have Red and Green Lights? (Decoding This Untapped Mystery)

If you love riding boats or traveling on long-distance ships, you must have come across the fact that every boat has red and green lights installed.

But, why do boats have red and green lights?

Well, we install red and green lights in boat as a safety precaution. In fact, they indicate that you are close to another vessel; hence you must act quickly to avoid a collision.

Why Do Boats Have Red and Green Lights
Why Do Boats Have Red and Green Lights?

Why Do Boats Have Red and Green Lights? (The Actual Answer)

Generally, the red and green lights in boats are termed side-lights. The red and green lights act as signals for your boat or any other vessel that is heading towards your vessel from sideways or from the opposite direction.

The red light indicates the boat’s left side, while on the other hand, the green light indicates the vessel’s right or starboard side.

This blog will learn about red and green lights on boats in detail and why you need to have a clear picture of the different lights used in boats.

Do you have to have red and green lights on a boat? 

Are you excited for the first ride on the boat earned from your hard work?

You must consider all the mandatory safety features to ensure that you are not the reason for the collision in the mid-river. Well, collision with another boat inside the river can be life-threatening for people from both ends.

According to a recent study, most accidents occur during winters or the dark, and having a red and green light on your boat can help you prevent accidents.

As mentioned above, red and green lights are mandatory lights that every boat owner must install on their boat to avoid collision with any other vessel. 

So, it is your responsibility to ensure that you install green and red lights on your boat to safeguard your boat and, most importantly, your loved ones with whom you will be riding on the boat. 

Boat Navigation Light Rules: 

Navigation lights are a set of lights that are mostly used in ships and aircraft at the time of dawn during sunset and sunrise and during fog and rain to showcase its presence to all other vessels.

  • As per US law, all boats under 12 meters must have separate or combined masthead or stern light. Every boat owner must also equip sidelights and all-around white lights to prevent collisions.
  • On the other hand, power-driven boats having a size of fewer than seven meters and speed not exceeding 7 knots can either have combined side-lights or an all-around white light. 
  • The green and red lights must at least be visible one mile away on a clear dark night.

As a boat owner, it is your duty to install boat navigation lights as per the law. Moreover, you must install boat navigation lights to abide by the state law and ensure that you have a safe journey during extreme weather conditions or during the dark.

What Does a Red and Green Light Indicate When Seen Together at Night?

By now, you must be well-aware of the fact that the red and green lights are an important part of your boat safety. The red and green lights will help the observer in understanding from what side the boat is coming, either the port side or starboard side. 

Red and Green Light of a boat
Red and Green Light of a boat

Similarly, different lights indicate different ways of approaching the boat and what way you should proceed to avoid a collision.

For example, if you can see the red and green light, then you are heading straight towards the boat coming from the opposite direction. In such a case, you will have to provide space on your starboard side to ensure that the other vessel can safely travel.

At the same time, if you can only see the white light of the boat, it means you have to overtake the vehicle to avoid a collision.

What Lights are Required on a Pontoon Boat?

When you are sailing during winter or night, it is quite important for you to install lights on your pontoon boat. Navigation lights can improve your vision, and you can also easily overcome obstacles inside water. 

Apart from their functional purpose, you can also decorate your pontoon with a combination of different lights. 

Here are a few instructions on what kind of lights your pontoon must-have for a safer ride.

  • A green light on the starboard side and a red light on the port side, and a white light at the center to ensure that you are visible to all other boats inside the zone.
  • All-round lights with white light with a 360-degree view.
  • Most pontoon boats start lingering late in the evening; safety becomes a paramount concern; hence, you can also install LED lights on your pontoon boat for safety and beauty. 

Why Are Port Red and Starboard Green?

Generally, the port side means left, and the starboard side means right, and the same system is followed while providing light colors for both sides.

You will find the red light on the port side in all the boats, while you will find the green light on the starboard side. 

Why Are Port Red and Starboard Green
Why Are Port Red and Starboard Green?

Lack of light is one of the prominent reasons behind accidents in water; hence red and green lights have proven quite worthy in preventing vessel collisions.

The same color formula also helps in accurately predicting the position of the vessel hence preventing a collision. 

On the other hand, you will have to ensure that large ships can only turn 45 degrees on both starboard and port side. But small boats can efficiently turn up to 150 degrees. 

What Determines the Navigation Lights You are Required to Display on a Boat?

There is also a certain factor that can play a huge role in determining your boat’s navigation lights.

Here are a few factors you can consider when the concern is about navigation lights you must display on a boat.

Navigation Lights on a Boat
Navigation Lights on a Boat

Power-Driven or Air-Cushioned Boats:

Most of the power-driven or air-cushioned boats display the same light, but the only difference between power-driven and air-cushioned is they have a huge mast headlight while the same cannot be found in air-cushioned boats.


Underway refers to boats that are in motion but is also used to coin the momentum created by the wind on the boat.

The vessel’s not under command:

If there is no captain on the boat, the vessels will showcase two red lights signaling there is no captain on board or the captain’s dead.


Get your all questioned answered here:

When Should Navigation Lights be Shown?

Navigation lights can be shown during sunset or sunrise or during fog or winter as visibility is quite low. Hence, navigation lights can help provide the right detail from which direction the vessel is coming from. 

Why do Boats Use Red Interior Lights?

One of the prominent reasons for the red interior lights is human vision. White light reduces the eyesight because of its brightness, while the red light enhances your eyesight and visibility range; hence you don’t have to compromise with your vision.

Do all boats need navigation lights?

Generally, all the boats must have navigation lights to ensure they don’t collide with other vessels. If you have a smaller vessel, you can go with white round light on the head and red and green light on the port and starboard side, respectively.

What boat  lights need to be on at night?

Red and green lights are mandatory for all the boats that operate at night. For all the boats between 12-20 meters, the navigation lights must be visible from a range of 2 km.

Final Thoughts

Green and red navigation lights play a pivotal role in preventing accidents during the night or in fog. They also help understand the direction of the vessel and how you should move to avoid a collision.

When buying navigation lights, you will have to ensure the type of your boat and purchase accordingly. 

Rocky D

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