190. NAV LIGHTS EXPLAINED: What Every Boater Must Understand
This Is Not Optional Knowledge
Navigation lights are not just for visibility — they are a language.
They tell other vessels:
- what you are doing
- how you are moving
- what your limitations are
If you don’t understand them:
👉 you are operating blind at night
Basic Navigation Lights (Power-Driven Vessel Underway)
Most recreational boats will display:
- Red light (port side)
- Green light (starboard side)
- White light (stern + masthead)
What Others See
- Red = your left side
- Green = your right side
👉 This tells them how to avoid you
At Anchor (Moored)
A vessel at anchor must display:
👉 All-around white light
Meaning:
- you are not moving
- others must avoid you
Towing Configuration (Very Important)
A towing vessel displays:
👉 Two or three white masthead lights in a vertical line
👉 Sidelights (red/green)
👉 Yellow towing light above stern light
What It Means
- vessel has limited maneuverability
- tow may extend far behind
👉 DO NOT cross close behind
Fishing Vessels
Fishing vessels display:
- Red over White → “Fishing at night”
Meaning:
👉 restricted maneuverability
Vessel Not Under Command
Displays:
👉 Two red lights (vertical)
Meaning:
- vessel cannot maneuver
- YOU must avoid them
Why This Matters in Real Life
At night, you don’t see boats first.
👉 you see their lights
And you must decide:
- crossing?
- overtaking?
- head-on?
👉 in seconds
Common Mistakes
- wrong lights turned on
- anchor light not used
- confusing deck lights with nav lights
- ignoring what other vessels are displaying
Real-World Scenario
You see:
👉 green light only
That means:
- you are looking at their starboard side
- they are crossing from your left
👉 You are the give-way vessel
Learn the Rules (Authoritative Source)
For full navigation rules:
Refer to:
U.S. Coast Guard Navigation Center
https://www.navcen.uscg.gov/navigation-rules
Final Thought
Navigation lights are not decoration.
👉 They are communication.
And if you don’t understand them, you are not in control at night.