nautical rules of the road

CHAPTER 1

NAUTICAL RULES OF THE ROAD

Nautical traffic laws

are known as the

Nautical Rules of

of the Road.

Nautical Rules of the Road were first

established in 1897 by all maritime

nations of the world. The latest major

revision was in 1972.

International Inland

International Rules of the Road

The official name is The International

Regulations for Preventing Collisions

at Sea, 1972, or ―the 72 COLREGS.‖

Convention on the International

Regulations for Preventing Collisions

at Sea, 1972 (COLREGs)

The COLREGs include 38 rules divided

into five sections:

• Part A - General

• Part B - Steering and Sailing

• Part C - Lights and Shapes

• Part D - Sound and Light Signals

• Part E - Exemptions

The inland rules for the U.S. were

established by Congress under The

Inland Navigational Rules Act of 1980.

Inland Waters – Unified Rules

Purpose of

the Rules

Prevent

Collisions

The rules govern all

waterborne traffic.

Power Vessel

Propelled by

machinery, even

if under sail

Sailing Vessel

Under sail alone,

even if machinery

is aboard

A vessel is underway

when not:

• Anchored

• Moored to a dock

or buoy

• Aground

A vessel that is not anchored,

moored, or aground

It is not required that you are

moving or making way.

Underway

Both international and inland rules of

the road cover:

• Lights and shapes

• Sound signals

• Steering and sailing rules

• Distress signals

Maritime courts

of law use both

international and

inland rules after

a collision to

decide who will

pay for damages.

Display lights from sunset to sunrise

and in periods of restricted visibility.

Do not display lights that could be

mistaken for required lights.

Running Lights

(Port, Starboard, and Stern)

Running Lights

(Masthead and Range)

Any of various lights required to

be displayed by vessels operating

between sunset and sunrise

Running Lights

Running lights are white, red, and

green lights carried by all seagoing

power-driven vessels underway.

Masthead Light

225°

The white light in the fore part of the ship

is required for all ocean-going ships.

All-around white light.

Masthead Light

(Vessels less

than 12 meters,

39 feet)

360°

Range Light

(Vessels over 50 meters or 150 feet)

Masthead Light

Range Light

(15 feet higher than

Masthead Light)

Stern Light

A ship underway must display a white

stern light.

12 Pts.

135°

Running Lights

Port

Starboard

112.5°

112.5°

What side of a vessel is called the port

side, and what color is its sidelight?

What side of a vessel is called the

starboard side, and what color is its

sidelight?

What side of a vessel is called the port

side, and what color is its sidelight?

Left and red

What side of a vessel is called the

starboard side, and what color is its

sidelight?

Right and green

An easy way to remember is

―Port wine is red.‖

The angular dimension (horizontal

arc in degrees) within which a light

can be seen from a location off the

vessel

Arc of Visibility

What is the required arc of visibility, in

degrees, of the following ship’s lights?

Masthead light:

Sidelights:

All-around light:

Stern light:

What is the required arc of visibility, in

degrees, of the following ship’s lights?

Masthead light:

Sidelights:

All-around light:

Stern light:

225°

112.5°

360°

135°

The white masthead and range lights, together with

sidelights, indicate the course of the sighted ship.

The white stern light warns overtaking

ships that another ship is ahead.

―Reading‖ Navigation Lights

(Vessels Underway)

―Reading‖ Navigation Lights

(Vessels Underway)

STAR-

BOARDPORT

B

O

W

S

T

E

R

N

The upper white lights must be visible

from a distance of at least 5 miles.

The port and

starboard sidelights

and the stern light

must be visible at

least 2 miles away.

International Maritime Organization (IMO)

The international and inland rules agree

in the arcs of visibility required by the

lights shown.

Power-driven motorboats

• Range light optional

• Masthead light visible for at least 3 miles

• Stern and sidelights visible for 1 mile

Pilot Boat

A boat carrying pilots to or from

large ships

Pilot Boat

Pilot Boat

―White over red, pilot ahead‖

is a memory aid used when

looking for a pilot boat.

Pilot Boat

A vessel engaged in pilotage duties may

sound an optional identity signal of four

short blasts on its horn.

Vessel at Anchor

Ships less than 50 meters in length at anchor

show an all-around white light forward.

Ships more than 50 meters in length show an

all-around white light forward and aft.

Vessel at Anchor

In daytime, vessels

at anchor must display

a black ball, known as a dayshape.

Dayshape

Vessel at Anchor

Dayshape

Vessel Towing

Vessels towing must:

• Display two masthead lights in

a vertical line.

• If the tow extends beyond 200

meters, a third light must be

added below the second light.

A ship or craft that is disabled and

cannot operate in accordance with

the Rules of the Road

Vessel Not under Command

Not Making Way

Day

Shape

Vessel Not under Command

Making Way

Day

Shape

Vessel Not under Command

A ship not under command at night must show

two red lights, one over the other. They must be

visible all around the horizon at a distance of 2

miles.

Vessels Not under

Command during

Daylight

Merchant ships will hoist two

black balls.

Naval vessels will hoist the

―5‖ flag and two black balls.

Other lights and day shapes are

prescribed for various operations

such as:

• Commercial fishing

• Cable laying

• Underwater or diving operations

• Dredging

Some examples of day shapes follow.

Special Rules for Naval Vessels

The horizontal separation of white lights

on destroyers and smaller ships is often

less than that required by the rules.

The white lights on aircraft carriers are

usually on the superstructure and off the

centerline.

Special lights such as speed lights,

carrier-landing lights, and colored

recognition lights may be shown on

naval vessels during certain operations.

During ship exercises, naval vessels

may show no lights at all.

In peacetime, however, if a merchant ship

approaches, lights are usually turned on.

MINESWEEPER

When lights are required, the three black

balls are replaced with three green lights.

Amber-colored intermittent flashing

beacon – 3 seconds on – 3 seconds

off when submarine running surfaced,

in addition to other required lights

Whistle Signals

Whistle signals are required by both sets

of rules for vessels maneuvering within

sight of one another.

INLAND

RULES

Signifies intention only. A response

IS required.

INTERNATIONAL

RULES

Signifies execution of maneuver.

A response is NOT required.

Duration Times for

Whistle Signals

Short Blast: TOOT

Prolonged: T - O - O - T

Long Blast: T – O – O – T

I 1 second I

I 4 - 6 seconds I

I 8 - 10 seconds I

INTERNATIONAL

1 Short Blast:

―I am altering

my course to

starboard.‖

INTERNATIONAL

2 Short Blasts:

―I am altering

my course to

port.‖

INTERNATIONAL

3 Short Blasts:

―My engines are

going astern.‖

INTERNATIONAL - INLAND

5 Short Blasts:

―DANGER!’

Confusion over whistle signals probably

causes more collisions than any other

part of the rules of the road.

Both international and inland rules

consider the situation in which two

ships are approaching each other

with the risk of collision. They are:

• Meeting

• Overtaking

• Crossing

Give-Way Vessel — Must keep clear

Stand-On Vessel — Has the right of way

The risk of a collision exists when

the bearing of an approaching vessel

remains constant.

A collision at sea can ruin your whole

day.

General Rules to Avoid Collision

1. Take action in ample time.

2. Make the passing agreement

signals.

3. Make obvious changes.

4. Check and recheck your actions

until clear of other vessels.

5. If necessary, stop or reverse your

engines.

INLAND

Meeting

Situation

One Short Blast

Port to Port

Give-way

Vessel

Give-way

Vessel

INTERNATIONALMeeting

SituationTwo Short Blasts

Starboard to Starboard

Give-way

Vessel

Give-way

Vessel

Only done if it is clearly the most convenient,

safe maneuver for both vessels.

INTERNATIONAL

Meeting

SituationTwo Short Blasts

Starboard to Starboard

It is implied that a starboard-to-starboard

passing is only proper when there is no risk

of collision.

There is an old nautical saying that

warns: ―Two short blasts are the first

two notes of the collision waltz.‖

In U.S. Inland Waters

Starboard-to-starboard passing is

authorized only if the ships are not

meeting end-on and safe passage is

assured without any maneuvering.

INTERNATIONAL

Crossing Situation

The give-way vessel is

required to maneuver to

avoid crossing ahead of

the stand-on vessel.

Give-way

Vessel

Stand-on

Vessel

INTERNATIONAL

Crossing Situation

This means reducing

speed, stopping, altering

course to starboard, or

backing down.

Give-way

Vessel

Stand-on

Vessel

INTERNATIONAL

Crossing

Situation

One Short Blast

Two Short Blasts

Three Short Blasts

Give-way

Vessel

Stand-on

Vessel

In inland waters, the overtaking vessel

must signal on which side it intends to

pass; one blast to starboard and two

blasts to port.

It cannot pass until it hears the same

signal from the overtaken vessel.

Overtaking Situation

INTERNATIONAL

In international waters, a ship that can pass

another without a change of course may do

so without a signal.

Overtaking Situation

INTERNATIONALOvertaking Situation

If overtaking vessel must change course to

pass, she sounds one short blast if turning

to the right, or two short blasts if turning to

the left, and does not have to wait for an

answer.

Vessel being overtaken may respond with 5

or more short blasts if she considers

proposed maneuver dangerous.

I

N

L

A

N

D

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U

L

E

S

Overtaking Situation

An overtaking vessel must give a signal

whether or not she must change course

to pass, and she may not pass until she

hears the agreeing signal from the vessel

ahead.

The signals are one short blast if

proposing to pass the other vessel on her

starboard side, and two if proposing to

pass on her port side.

I

N

L

A

N

D

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Overtaking Situation

Vessel being overtaken

responses with 5 short

blasts indicating danger

to port.

Overtaking vessel

indicates overtaking

on the port side by

2 short blasts.

This is followed by a signal for

what is considered the safer

procedure and the overtaking

vessel answers signal and

passes on the correct side.

DANGER

Avoid Collision – ―In Extremis‖

A vessel may depart from the requirements

of the rules of the road when there is

imminent danger of collision. Such a

danger of collision is called ―in extremis.‖

A ship’s captain is

required to use good

judgment to avoid

collision even if the

action might violate

the rules.

Fog Signals Underway

Inland Rules

Prolonged blast 4 to 6

seconds on the whistle

at 1-minute intervals

International Rules

Prolonged blast 4 to 6

seconds on the whistle

every 2 minutes

Inland Rules

Fog Signal at Anchor

Ring the bell for about

5 seconds at 1-minute

intervals.

In restricted visibility, you must:

Go at a safe speed.

Maintain a proper look-out.

Display navigation lights.

If you hear a fog signal forward of your

beam:

Reduce speed to bare steerageway.

The minimum speed at which the

rudder is effective

or

The minimum speed at which your

vessel can be kept on course

Steerageway

Distress Signals

for

Inland & International Rules

FOGHORN

CONTINUOUS

SOUNDING

GUN FIRED AT

INTERVALS

OF 1 MINUTE

FLAMES ON

A VESSEL

(NIGHT ONLY)

NAUTICAL RULES OF THE ROAD

THE END

Distress Signals

for

International Rules

Gun Fired at 1-Minute Intervals

Distress Signals

for

International Rules

Continuous Sounding of Foghorn

Distress Signals

for

International Rules

Rockets or Shells

Distress Signals

for

International Rules

SOS

Distress Signals

for

International Rules

Signal ―MAYDAY‖ by Radio

Distress Signals

for

International Rules

Flaghoist with November Charlie

Distress Signals

for

International Rules

Square Flag and Ball

Distress Signals

for

International Rules

Flames from Tar or Oil Barrel

Distress Signals

for

International Rules

Parachute Flare

Distress Signals

for

International Rules

Smoke Signal

Distress Signals

for

International Rules

Wave Arms

Q.1. Name the two sets of rules of

the road used by ships in the

United States.

Q.1. Name the two sets of rules of

the road used by ships in the

United States.

A.1. The International Regulations

for Preventing Collisions at

Sea, 1972, and The Inland

Navigational Rules Act of

1980

Q.2. What is the purpose of the rules

of the road?

Q.2. What is the purpose of the rules

of the road?

A.2. To prevent ship collisions

Q.3. How can you determine if risk

of collision exists?

Q.3. How can you determine if risk

of collision exists?

A.3. If the compass bearing of an

approaching vessel does not

appreciably change as the

range decreases (―constant

bearing decreasing range‖)

Q.4. What do the rules of the road

cover?

Q.4. What do the rules of the road

cover?

A.4. Lights and shapes, sound

signals, steering and sailing

rules, and distress signals

Q.5. Explain the difference between

power-driven and sailing

vessels.

Q.5. Explain the difference between

power-driven and sailing

vessels.

A.5. A power-driven vessel is one

that is being propelled by

machinery even if she is

equipped with sails. A sailing

vessel is any vessel which is

being propelled by sail alone.

Q.6. What is the definition of

―underway?‖

Q.6. What is the definition of

―underway?‖

A.6. Any vessel not at anchor;

moored to a buoy or dock or

not aground

Q.7. What additional white light

must be shown for vessels 50

meters or more in length?

Q.7. What additional white light

must be shown for vessels 50

meters or more in length?

A.7. A range light

Q.8. Name the colors of the lights

used aboard ships.

Q.8. Name the colors of the lights

used aboard ships.

A.8. White, red, and green (and

amber for special

circumstances)

Q.9. What color is the masthead

light?

Q.9. What color is the masthead

light?

A.9. White

Q.10. State the colors of the port

and starboard sidelights.

Q.10. State the colors of the port

and starboard sidelights.

A.10. Red on the port, green on the

starboard

Q.11. Why are special rules made

for lights on naval vessels?

Q.11. Why are special rules made

for lights on naval vessels?

A.11. Construction and mission

requirements

Q.12. What is the meaning of one

short blast of a ship's whistle

in international waters?

Q.12. What is the meaning of one

short blast of a ship's whistle

in international waters?

A.12. I am changing course to

starboard.

Q.13. What is the whistle signal for

danger?

Q.13. What is the whistle signal for

danger?

A.13. Five or more short blasts

Q.14. What is the meaning of one

short blast of a ship’s whistle

in inland waters?

Q.14. What is the meaning of one

short blast of a ship’s whistle

in inland waters?

A.14. It is a signal of intention to

pass port to port and only

executed if acknowledged by

the other vessel.

Q.15. When is a vessel required to

fly the national ensign upside

down as a signal?

Q.15. When is a vessel required to

fly the national ensign upside

down as a signal?

A.15. Never

Q.16. According to the rules, what is

the vessel called that must

take action in any given

situation?

Q.16. According to the rules, what is

the vessel called that must

take action in any given

situation?

A.16. Give-way

Q.17. Briefly explain what the Rule

of Good Seamanship states.

Q.17. Briefly explain what the Rule

of Good Seamanship states.

A.17. A ship's master must

exercise professional

judgment and may deviate

from the rules if a possible

dangerous situation arises

Q.18. In a crossing situation, which

vessel is the stand-on vessel?

Q.18. In a crossing situation, which

vessel is the stand-on vessel?

A.18. The vessel to the starboard

of the other

Q.19. In a meeting situation, which

vessel is the stand-on vessel?

Q.19. In a meeting situation, which

vessel is the stand-on vessel?

A.19. Neither, they are both

designated give-way vessels

Q.20. In an overtaking situation,

which vessel is the stand-on

vessel?

Q.20. In an overtaking situation,

which vessel is the stand-on

vessel?

A.20. The vessel being overtaken

(passed)

Q.21. What signal must a vessel

sound if, when rounding a

bend, it is unable to see for at

least ½ mile?

Q.21. What signal must a vessel

sound if, when rounding a

bend, it is unable to see for at

least ½ mile?

A.21. A prolonged blast of its

whistle (4 to 6 seconds)

Q.22. What do two short blasts of a

ship's whistle signal in

international waters?

Q.22. What do two short blasts of a

ship's whistle signal in

international waters?

A.22. Changing course to port

Q.23. What do three short blasts of

a ship's whistle signal?

Q.23. What do three short blasts of

a ship's whistle signal?

A.23. Engine backing (going

astern)

Q.24. In conditions of reduced

visibility, what signal does a

power-driven vessel underway

and making way sound?

Q.24. In conditions of reduced

visibility, what signal does a

power-driven vessel underway

and making way sound?

A.24. One prolonged blast at least

every 2 minutes

The white light on the aftermast

of vessels 50 meters or more

Range Light

Either of two lights carried by a

vessel underway at night, a red

one on the port side and a green

one on the starboard

Sidelights

Day Shape

(Black Ball)

A metal ribbing

roughly oval in

shape, over which

canvas is stretched

Obstructed View

1 Prolong Blast

I

N

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A

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D

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S

Change of Status

(leaving a dock or berth)

1 prolong blast

I

N

L

A

N

D

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E

S

Leaving a Dock or Berth in Reverse

1 prolonged blast, (change of status)

then 3 short blasts, (making sternway)

VESSEL AT ANCHOR

At night, ―Red over red, the captain is

dead‖ may help you remember the

vessel is not under command.

VESSEL NOT UNDER COMMAND

VESSEL AGROUND

VESSEL TOWING ASTERN, TOW LENGTH

MORE THAN 200 METERS ASTERN

SAILING VESSEL UNDER POWER

VESSEL ENGAGED IN FISHING

VESSEL ENGAGED IN FISHING, GEAR

EXTENDING MORE THAN 150 METERS

VESSEL CONSTRAINED BY DRAFT

VESSEL ENGAGED IN

MINESWEEPING

VESSEL RESTRICTED IN ABILITY TO

MANEUVER

VESSEL RESTRICTED IN ABILITY TO

MANEUVER, OBSTRUCTION EXISTS ON SIDE

WITH TWO BALLS

I

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Meeting

Situation

Two Short Blasts

Starboard to Starboard

Meeting

SituationOne Short Blast

Port to Port

Give-way

Vessel

Give-way

Vessel

Give-way

Vessel

Give-way

Vessel

I

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In inland waters,

starboard-to-

starboard passing

is authorized only

if ships are not

meeting end-on

and safe passage

is assured

without any

maneuvering.

One Short Blast

Port to Port

Crossing Situation