Buzz
A comprehensive guide to sternlights, masthead lights, and sidelight specifications for boats of various sizes. Learn about the importance of proper lighting for safe navigation at night on the water.
Key Points to Note
- A boat's sternlight is white and shines over a 135-degree angle behind the boat, visible from 2 nautical miles away.
- Masthead lights are also white, illuminating a 225-degree angle in front of the boat, while sidelights are red (port) and green (starboard).
- Boats under 12 meters long can use a single, white all-around light instead of separate masthead and sternlights.
Steps to Follow
Understanding Sternlight Color and Visibility Requirements
The sternlight, which is white and covers a 135-degree angle behind the boat, serves as an important safety feature for boats navigating in low visibility conditions. It must be visible from a distance of 2 nautical miles and is typically activated from sunset to sundown or during adverse weather.
Exploring Other Navigation Lights
Masthead lights are white and illuminate a 225-degree angle in front of the boat. They are positioned higher than sidelights and have visibility requirements based on the boat's length. The port light is red, and the starboard light is green, helping indicate the direction of travel at night.
The sidelights, with red for port (left) and green for starboard (right), assist in determining the boat's direction from afar at night. They are optional for smaller boats and must be visible from specific distances based on the boat's size.
On small boats, a white all-around light replaces masthead and sternlights. These all-around lights are visible from 360 degrees and can be used on boats under 12 meters long. They are typically positioned at least 39 inches above the sidelights.
Navigation Light Requirements Based on Boat Size and Type
For boats up to 7 meters (23 feet), including short powerboats and sailboats, an all-around white light is mandatory. Optional colored sidelights are recommended to enhance visibility. This rule also applies to paddle-driven vessels like canoes, kayaks, and rowboats.
Mid-sized powerboats up to 12 meters (39 feet) require a visible white all-around light from 2 nautical miles away, along with red and green sidelights visible from 1 nautical mile away.
Sailboats up to 20 meters (66 feet) sailing at night must have a white sternlight visible from 2 nautical miles away and colored sidelights visible from 1 nautical mile away. They can use either separate white, red, and green lights or a tricolor combination light.
For powerboats up to 20 meters (66 feet), separate masthead and sternlights are required. The masthead light must be visible from 3 nautical miles away, while the sternlight and colored sidelights need to be visible from 2 nautical miles away.
All boats over 20 meters (66 feet) must have a sternlight and colored sidelights visible from 2 nautical miles away, along with a masthead light visible from 5 nautical miles away.
All boats under 50 meters (160 feet) at anchor need an all-around white light visible from 2 nautical miles away unless anchored in a well-lit marina.
Useful Tips
- Basic navigation light rules are established by the U.S. Coast Guard. Additional or stricter regulations may apply based on state or local requirements.
Important Warnings
- Decorative or recreational lights must not obstruct or cover any of your boat's navigation lights, as it is against the law.
