Boat Navigation Light Rules In Plain English (Day & Night)

In Boating by Christopher Schopf

Boat navigation light rules can be a little difficult for newcomers to understand.  This is probably because these light rules can change depending on a wide variety of factors.

Failing to comply with these rules can leave you open to legal trouble as well as lawsuits. 

Also, knowing these rules will help to keep you and other boaters safe while out on the water so it really is essential that you learn and remember them.

Here’s everything you should know about the boat navigation light rules.

Why Have Boat Navigation Light Rules At All

Boat navigation light rules help boaters communicate with each other.  They also help to determine who has the right of way.  This is important as it determines what actions boats will take as they pass one another.

Without these guidelines, there would be many more accidents out on the water as people simply wouldn’t know how to interact with each other.

Remember, when you’re out on the open water, there aren’t any designated lanes to follow and without rules, boaters can easily become confused about which way they should turn or whether or not they should even turn at all.

On top of this, these rules help establish methods for boaters to tell each other when they’re anchored or when they’re in distress.  Use your lights correctly when you need help and you’re much more likely to get it.

When do I Need to Follow Boat Navigation Light Rules?

Light rules apply any time between sunset and sunrise.  They also apply any time visibility is low.

An example of this could be during foggy or rainy weather.

A more unusual example of this could be during a solar eclipse.  Basically, if you feel that having the lights on will help others see you better then it’s a good idea to turn them on.

The Different Light Rules by Boat and Size

Different types of boats will have different light rules that they need to follow.  These sets of rules are broken down based on whether or not the boat is a sailboat or a powered boat.

Once this is established, the rules are then broken down by size.

The different sizes to consider are boats shorter than 39.4 feet, boats sized between 39.4 and 65.6 feet and boats greater than 65.6 feet.

If you’re wondering why the numbers are so precise it’s because this is the conversion from meters.  39.4 feet equals 12 meters and 65.6 feet equals 20 meters.

Generally, all boats will have a red light on their port side and a green light on their starboard side.  To put it in plain English, if you’re in the driver’s seat, the red light goes on the left and the green light goes on the right.

A white light should be at the stern of the boat.  The stern is the rear of the boat.

Powered Boat Light Placement

Here are the lights you’ll need when operating a powered boat depending on the size of the boat you’re operating.

  • Boats less than 12 meters or 39.4 feet long:

For these boats, you’ll need one red light and one green light at the front port and starboard sides of the boat.  These lights should be positioned so that they can be seen at an angle of 112.5 degrees.  They should also be strong enough to be seen from a mile away.

You’ll also need to mount them towards the bow of the boat.  This is otherwise known as the front of the boat.

Additionally, you’ll need one white light that can be seen from all angles.  It should be strong enough to be seen from two miles away. 

Also, this light will need to be mounted at least 39 inches or 99 centimeters higher than the red and green lights.

  • Boats greater than 12 meters or 39.4 feet but less than 20 meters or 65.6 feet:

With boats of this size, you’ll still need your red and green light, but your white lights will change.  In this case, you’ll mount a red light to your port or left side and a green light to your starboard or right side.

These lights will need to be seen from an angle of 112.5 degrees and they’ll need to be seen from a distance of one mile.

The two white lights will need to be mounted at the stern and masthead of the boat.  Stern lights can also be referred to as the aft light.  Either way, it just means the light at the back of the boat.

This light will need to be seen from a 225-degree angle facing the rear.  It needs to be strong enough to be seen from 2 miles away.

The masthead light is at the forward position of the boat.  This light is mounted on the masthead and it must cover a 135-degree angle.

The light will need to be visible from 2 miles away.

Masthead lights must be mounted at least 8 feet above the gunnel.  The gunnel is the top edge of the side of the boat.

  • Boats larger than 20 meters or 65.6 feet long:

To operate a non-commercial boat that is over 20 meters or 65.6 meters long, you’ll have to have the same lights in the same positions as the smaller boats.  However, you’ll also need to add matt black inboard screens to your side lights.

Sail Boats and Other Unpowered Boats

These boats can be broken down into two different size categories.

These two categories are boats that are under 23 feet or 7 meters and boats that are over 23 feet or 7 meters.

Unpowered boats such as sailboats, rowboats, and kayaks under 23 feet in length only need to have a white light on them.  This white light can be anything from a flashlight to a lantern.

However, you can still opt to place red and green lights at their appropriate places.

Larger sailboats will need to have a 135 degree white light at the stern and 112.5 degree red and green lights at the port and starboard sides.  The white light should be visible from 2 miles away while the red and green lights should be visible from 1 mile away.

Alternatively, a tri-color light could be placed on the masthead.

This light will have all three lights built into it and it should be visible from at least 2 miles away.

Advice For All Boats Regarding Light

Regardless of what boat size you’re on, it is a good idea to have a flashlight with you.

In the event that your boat lights become inoperable, you’ll at least have one light that you can signal with.

Should you find yourself on the water at night in a disabled boat, your flashlight may be the only thing keeping you from being crashed into.

Light Rules For Boats at Anchor

When you’re anchored at a marina or dock, you won’t have to worry about specific boat light rules and regulations.

However, when you’re anchored out on the water, it is critical that you follow boat light rules as this will help keep other boaters from running into you.

It will also help establish that you have the right of way so you won’t have to move every time a larger boat comes your way.

Of course, having the right lights doesn’t mean you’ll be able to anchor just anywhere.  You’ll still have to follow any inland rules when it comes to anchoring your boat.

When anchored, you’ll need to display an all-around white light that lets other boaters know your position.  This light should be placed where it can best be seen by other boaters.  For example, a sailboat might put this light at the top of their mast.

Boats Under Distress

Boats under distress should display what is known as a visual distress signal so that they can get help.  At night, these distress signals will come in the form of flares, buoyant flares, and lights.

You should have at least three devices on your boat to use for signaling. 

This could come in a variety of forms and you can use the same one three times.  For example, your three devices could be having three signaling flares with you.

Only use these lights when you’re in danger.  Failure to do so can result in heavy fines and potential imprisonment.

Determining Who Has The Right of Way

When you come across another boat and you can only see a white light then you’ll know that you’re either approaching an anchored vessel or a vessel that is moving in front of you.  In this case, you can overtake them and go around them from either side.

If you come across a green light and a white light then you have the right of way.  In boating terms, this means that you are the stand-on vessel.

Technically speaking, the other boat should give way and you won’t have to worry about moving.

However, there is always a chance that the other person will not give way for some reason and you should be ready to move.  You never know, the other boater may not see you or they may not know the rules as they should.  Remember, being right won’t mean anything if you end up dead in a boat crash.

If you come across a red and white light, you are the one that needs to give way.  In this case, you’ll want to slow your boat down and pass by them on their right.

In all of these scenarios I described, you were in a powered vessel and you were passing a powered boat or a sailboat that was driving while under power.

However, what happens when you encounter a sailboat or other unpowered vessel in a powered vessel?

In this case, you’ll see a red light, a green light, or a white light, but you won’t see all three.  Regardless of what you see, you’ll want to give way.  This is because these boats can’t maneuver as well as you and they probably won’t be able to get out of your way before you come across them.

At this point, you can see why different boats need different types of lights and why it’s important to use the lights that apply to your particular craft.  Use the wrong lights and you’ll confuse the other boaters around you.  This could easily lead to an accident that could have easily been avoided.

What About Boaters Who Are Color Blind?

Unfortunately, people who are color blind won’t be able to safely operate a boat at night by themselves.

Also, they won’t be able to get a captain’s license as you need to be able to pass a color blind test to get this license. Here’s an article we wrote about all you need to know about boat license types (with prices).

If you’d like to do some recreational boating at night but you can’t differentiate between the colors red and green, you might want to consider bringing a friend along.

This way, your friend can tell you what colors you’re coming up on so that you can safely navigate yourself past other boats.

4 Types of Boat Lights

  1. The red and green lights that go on the sides of a boat are known as side lights.
  2. White lights that only face backward are known as stern lights and white lights that face forward are known as masthead lights.
  3. An all-round white light is a white light that faces 360 degrees.  These lights are used on smaller boats and on boats that are at anchor.  They can be replaced by making use of a stern light and a masthead light.
  4. Another type of light is the tri-color light. 
    A tri-color light can be used on a sailboat to portray the white, green, and red lights. Bi-color lights are also available for small powered boats and sailboats.  These lights display both red and green light.

The combination of lights that are displayed will always give the boater a 360-degree field of light.

This ensures that other boaters can see them no matter where they are in relation to each other.

Safety Precautions To Be Aware Of

Even new boats can have lights that weren’t configured correctly or lights that simply don’t work.

It’s important that you check these lights before you head out on the water.

This is true even if you don’t intend on staying out after dark.  After all, it’s always possible that you could become stranded until after dark or that it could become too foggy to operate out on the water without lights.

Other Things You Should Know About Boating At Night

Boat navigational light rules are critical for night time boating but there are other things to consider as well.

One thing to consider when boating at night is the use of a lookout.

Having one of your passengers act as a lookout will make it more likely that you’ll spot problems in advance.

Remember, other boaters aren’t the only potential hazards you can run into at night.  Shallow shipwrecks, low water depths, and unlit piers, docks and jetties can also become hazards if they aren’t noticed in time for you to avoid them.

High Beams

High beams should be used for docking purposes only.  This is because using them while on the water can confuse other boaters.

Also, the high beams can shine into other sailor’s eyes and can give them night blindness.

Just think about it this way.

It isn’t safe to drive towards another car with your high beams on, so why would it be safe to drive towards another boat with high beams on?

Driving Speed

Night time boating should be done at slower speeds than day time boating.  The primary reason for this is that visibility is more limited at night.

Driving slower will help to give you more time to react to boaters and other hazards.

Also, when you first start boating, you’ll still have to take a moment to think about the lights that you see.  Driving at a slower speed will give you this additional moment without affecting your safety.

Not All Lights On The Water Are Boats!

I’ll end this post with a funny story I once heard about a boat traveling at night.  This story has changed many times over the years but the gist of it’s still the same.

It goes like this:

A large vessel was traveling at night when they came across a white light in front of them.  The captain of the ship immediately got on the radio and contacted the other vessel to demand that they get out of the way.

The other vessel responded by telling the captain to change his course.  To this, the captain responded with, “This is the warship the USS Enterprise and I demand you change course or we’ll be forced to take action!”.

To this, the other vessel responded with, “This is a lighthouse and you are on course to become shipwrecked.”.

This isn’t a real story and now that you know proper boat navigation light rules, it is a story that could never happen to you. 

If you came across a white light and thought it was a boat, you’d assume it was unpowered or at anchor and you’d simply take steps to go around it.