Boat Lights Red And Green – A Guide to Navigation Lighting

Reviewed By Boatsbuilding Expert

Navigating the open waters is an exhilarating experience, but it comes with the responsibility of ensuring safety for oneself and others.

Red and green boat navigation lights are crucial for maintaining safety on the water, enabling boaters to discern a vessel’s orientation and direction while complying with international and local regulations.

One crucial aspect of boating safety is the proper use of navigation lights, particularly the red and green lights found on most vessels.

It delves into the importance of these lights, relevant regulations, and best practices for installation and maintenance.

II. Anatomy of Red and Green Boat Lights

A. The Red (Port) Light

Positioned on the left side of the boat, the red light indicates the port side. It serves a crucial role in helping other boaters determine the direction a vessel is traveling, particularly during nighttime or in conditions with poor visibility.

B. The Green (Starboard) Light

Similarly, the green light is located on the right side of the boat, marking the starboard side. Like the red light, it helps other mariners discern the vessel’s orientation and movement.

C. Light Housing and Materials

Navigation lights are typically encased in durable, waterproof housings made from materials like stainless steel, aluminum, or high-quality plastic. These materials protect the lights from harsh marine environments and ensure longevity.

III. Navigational Rules and Regulations

A. International Regulations

COLREGS (Convention on the International Regulations for Preventing Collisions at Sea)

The International Maritime Organization (IMO) has established guidelines called COLREGS, which outline the proper use of navigation lights, including red and green lights, to prevent collisions between vessels.

B. US Coast Guard Requirements

In the United States, the Coast Guard mandates that all vessels operating between sunset and sunrise or during periods of reduced visibility must display navigation lights. These requirements also apply to anchored vessels.

C. Visibility Ranges and Arcs

Visibility ranges for red and green boat lights depend on the size of the vessel. Smaller boats typically require a visibility range of one to two nautical miles, while larger vessels necessitate a range of up to five nautical miles.

IV. Types of Red and Green Boat Lights

A. Incandescent Lights

Traditionally, incandescent bulbs were the standard for navigation lights. While they are still available, they consume more energy and have a shorter lifespan than modern alternatives.

B. LED Lights

Light Emitting Diode (LED) lights are increasingly popular due to their energy efficiency, longevity, and brightness. They also provide a consistent light output throughout their lifespan.

C. Solar-Powered Lights

Solar-powered navigation lights harness the sun’s energy during the day and store it in a battery for nighttime use. These lights are eco-friendly and can be an excellent option for vessels without an onboard power source.

D. Combination Lights

Some boats feature combination lights, which integrate red and green lights into a single unit. This design simplifies installation and maintenance while maintaining compliance with navigational rules.

V. Installation and Maintenance

A. Proper Positioning of Red and Green Lights

Red and green navigation lights should be installed at the bow, with the red light on the port side and the green light on the starboard side. They must be visible from the front and sides of the vessel to ensure other boaters can accurately determine the boat’s direction.

B. Electrical Wiring and Connections

Secure and watertight electrical connections are essential for the proper functioning of navigation lights. Regularly inspect the wiring for signs of wear or corrosion and replace as needed.

C. Routine Maintenance and Inspections

Periodically inspect navigation lights for damage, cleanliness, and functionality. Replace bulbs or LEDs as needed and clean the lenses to ensure optimal visibility.

D. Troubleshooting Common Issues

If navigation lights fail, check the wiring, connections, and switches for damage or corrosion. When replacing bulbs, consider upgrading to LED boat navigation lights for low power consumption and enhanced visibility.

VI. Additional Navigation Light Considerations

A. All-Around White Light

In addition to red and green sidelights, most vessels are required to display an all-around white light. This light is typically mounted on a pole-style fixture, ensuring visibility from all angles, and helps other boaters determine the position of the vessel.

B. Stern Lights and Masthead Lights

Stern lights are white lights mounted at the rear of the boat, while masthead lights are white lights installed at the top of the mast on sailboats. Both types of lights aid in collision avoidance by providing other vessels with a clear indication of the boat’s orientation.

C. Restricted Visibility

In situations with limited visibility, such as fog or heavy rain, navigation lights play a critical role in preventing collisions. Boats must follow the COLREGS guidelines for lighting configurations during periods of restricted visibility.

D. Right of Way and Give Way Vessel

Understanding navigation light configurations helps boaters identify which vessel has the right of way in various situations. The boat displaying a green LED strip on the starboard side, for example, is the give-way vessel and must yield to other boats.

VIII. Conclusion

Red and green boat navigation lights, along with other essential lighting configurations, ensure safety and compliance with international and local regulations.

Proper installation, maintenance, and understanding of these lights not only protect oneself but also contribute to the overall safety of the boating community.

By staying informed and vigilant, every boater can enjoy the open waters with confidence and peace of mind.


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

Yes, red and green lights are required on boats as they serve as navigation lights. The red light should be displayed on the port (left) side, and the green light should be displayed on the starboard (right) side. These lights help other boaters determine the direction a vessel is moving and improve safety during nighttime or periods of reduced visibility. The requirements for navigation lights are specified in international guidelines (COLREGS) and local regulations, such as the US Coast Guard requirements.

What does only a green light mean on a boat?

If you see only a green light on a boat, it indicates that you are looking at the starboard (right) side of the vessel. In this situation, you are likely the give-way vessel and should yield to the boat displaying the green light. This is because the boat with the green light is likely crossing your path from the right, and according to navigational rules, you should give way to vessels approaching from your starboard side.

Which side do you pass an oncoming boat?

When encountering an oncoming boat, the general rule is to pass on the port (left) side. This is known as the “port-to-port” rule. Both vessels should adjust their course to the right to facilitate a safe passing maneuver. However, it’s essential to monitor the other boat’s navigation lights and respond accordingly, as specific situations or local regulations may dictate a different approach.

Why do boats use red lights at night?

Boats use red lights at night, particularly in the cabin or at the helm, to help preserve night vision. Red light is less likely to cause the pupils to constrict, allowing the eyes to remain more sensitive to low-light conditions. This is important when navigating at night, as it enables boaters to see better in the darkness and maintain a clear view of their surroundings, charts, and instruments without compromising their night vision.
Fred Apstein
Fred Apstein is a man of many talents. He studied at Sustainable Community Development and Royal Roads University, but what he loves to do is sailing, building boats, cooking seafood, and picking up the pieces when things go wrong! He's been in business for over 40 years with no refrigeration on his sailboats - that means food drying and pickling became necessary skills