3. International Inland
Nautical Rules of the Road were first
established in 1897 by all maritime
nations of the world. The latest major
revision was in 1972.
4. International Rules of the Road
The official name is The International
Regulations for Preventing Collisions
at Sea, 1972, or ―the 72 COLREGS.‖
5. 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
6. Inland Waters – Unified Rules
The inland rules for the U.S. were
established by Congress under The
Inland Navigational Rules Act of 1980.
25. 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?
26. 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.‖
27. Arc of Visibility
The angular dimension (horizontal
arc in degrees) within which a light
can be seen from a location off the
vessel
28. What is the required arc of visibility, in
degrees, of the following ship’s lights?
Masthead light:
Sidelights:
All-around light:
Stern light:
29. What is the required arc of visibility, in
degrees, of the following ship’s lights?
Masthead light: 225°
Sidelights: 112.5°
All-around light: 360°
Stern light: 135°
30. The white masthead and range lights, together with
sidelights, indicate the course of the sighted ship.
31. The white stern light warns overtaking
ships that another ship is ahead.
41. Pilot Boat
―White over red, pilot ahead‖
is a memory aid used when
looking for a pilot boat.
42. Pilot Boat
A vessel engaged in pilotage duties may
sound an optional identity signal of four
short blasts on its horn.
43.
44. 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.
45. Vessel at Anchor
Dayshape
In daytime, vessels
at anchor must display
a black ball, known as a dayshape.
49. 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.
50.
51. Vessel Not under Command
A ship or craft that is disabled and
cannot operate in accordance with
the Rules of the Road
54. 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.
55. Vessels Not under
Command during
Daylight
Merchant ships will hoist two
black balls.
Naval vessels will hoist the
―5‖ flag and two black balls.
56.
57. 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.
58. 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.
59. 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.
60. During ship exercises, naval vessels
may show no lights at all.
In peacetime, however, if a merchant ship
approaches, lights are usually turned on.
61. When lights are required, the three black
balls are replaced with three green lights.
MINESWEEPER
64. INLAND
RULES
Signifies intention only. A response
IS required.
65. INTERNATIONAL
RULES
Signifies execution of maneuver.
A response is NOT required.
66. Duration Times for
Whistle Signals
Short Blast: TOOT
I 1 second I
Prolonged: T - O - O - T
I 4 - 6 seconds I
Long Blast: T – O – O – T
I 8 - 10 seconds I
67. INTERNATIONAL
1 Short Blast:
―I am altering
my course to
starboard.‖
68. INTERNATIONAL
2 Short Blasts:
―I am altering
my course to
port.‖
69. INTERNATIONAL
3 Short Blasts:
―My engines are
going astern.‖
72. Confusion over whistle signals probably
causes more collisions than any other
part of the rules of the road.
73. 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
74. Give-Way Vessel — Must keep clear
Stand-On Vessel — Has the right of way
75. The risk of a collision exists when
the bearing of an approaching vessel
remains constant.
78. 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.
79. INLAND
Meeting One Short Blast
Situation Port to Port
Give-way
Vessel
Give-way
Vessel
80. INTERNATIONAL
Meeting Two Short Blasts
Situation Starboard to Starboard
Only done if it is clearly the most convenient,
safe maneuver for both vessels.
Give-way
Vessel
Give-way
Vessel
81. INTERNATIONAL
Meeting Two Short Blasts
Situation 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.‖
82. 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.
83. INTERNATIONAL
Crossing Situation
Stand-on
Vessel
The give-way vessel is
Give-way required to maneuver to
Vessel avoid crossing ahead of
the stand-on vessel.
84. INTERNATIONAL
Crossing Situation
Stand-on
Vessel
This means reducing
Give-way speed, stopping, altering
Vessel course to starboard, or
backing down.
85. INTERNATIONAL
One Short Blast
Crossing Two Short Blasts
Situation Three Short Blasts
Stand-on
Vessel
Give-way
Vessel
86. Overtaking Situation
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.
87.
88. INTERNATIONAL
Overtaking Situation
In international waters, a ship that can pass
another without a change of course may do
so without a signal.
89. INTERNATIONAL
Overtaking 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.
90. Overtaking Situation
I An overtaking vessel must give a signal
N whether or not she must change course
L to pass, and she may not pass until she
A hears the agreeing signal from the vessel
N ahead.
D
The signals are one short blast if
proposing to pass the other vessel on her
R starboard side, and two if proposing to
U pass on her port side.
L
E
S
91. Overtaking Situation
I
N DANGER
L
A
N
D Vessel being overtaken
responses with 5 short
blasts indicating danger
R to port.
U
L Overtaking vessel
indicates overtaking This is followed by a signal for
E on the port side by what is considered the safer
procedure and the overtaking
S 2 short blasts.
vessel answers signal and
passes on the correct side.
92. 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.‖
93. A ship’s captain is
required to use good
judgment to avoid
collision even if the
action might violate
the rules.
94. 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
114. Q.1. Name the two sets of rules of
the road used by ships in the
United States.
115. 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
116. Q.2. What is the purpose of the rules
of the road?
117. Q.2. What is the purpose of the rules
of the road?
A.2. To prevent ship collisions
118. Q.3. How can you determine if risk
of collision exists?
119. 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‖)
121. Q.4. What do the rules of the road
cover?
A.4. Lights and shapes, sound
signals, steering and sailing
rules, and distress signals
122. Q.5. Explain the difference between
power-driven and sailing
vessels.
123. 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.
139. Q.13. What is the whistle signal for
danger?
A.13. Five or more short blasts
140. Q.14. What is the meaning of one
short blast of a ship’s whistle
in inland waters?
141. 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.
142. Q.15. When is a vessel required to
fly the national ensign upside
down as a signal?
143. Q.15. When is a vessel required to
fly the national ensign upside
down as a signal?
A.15. Never
144. Q.16. According to the rules, what is
the vessel called that must
take action in any given
situation?
145. Q.16. According to the rules, what is
the vessel called that must
take action in any given
situation?
A.16. Give-way
147. 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
148. Q.18. In a crossing situation, which
vessel is the stand-on vessel?
149. Q.18. In a crossing situation, which
vessel is the stand-on vessel?
A.18. The vessel to the starboard
of the other
150. Q.19. In a meeting situation, which
vessel is the stand-on vessel?
151. Q.19. In a meeting situation, which
vessel is the stand-on vessel?
A.19. Neither, they are both
designated give-way vessels
152. Q.20. In an overtaking situation,
which vessel is the stand-on
vessel?
153. Q.20. In an overtaking situation,
which vessel is the stand-on
vessel?
A.20. The vessel being overtaken
(passed)
154. Q.21. What signal must a vessel
sound if, when rounding a
bend, it is unable to see for at
least ½ mile?
155. 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)
156. Q.22. What do two short blasts of a
ship's whistle signal in
international waters?
157. Q.22. What do two short blasts of a
ship's whistle signal in
international waters?
A.22. Changing course to port
158. Q.23. What do three short blasts of
a ship's whistle signal?
159. Q.23. What do three short blasts of
a ship's whistle signal?
A.23. Engine backing (going
astern)
160. Q.24. In conditions of reduced
visibility, what signal does a
power-driven vessel underway
and making way sound?
161. 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
179. VESSEL RESTRICTED IN ABILITY TO
MANEUVER, OBSTRUCTION EXISTS ON SIDE
WITH TWO BALLS
180.
181. Meeting Two Short Blasts
Situation Starboard to Starboard
I
N
Give-way
L Vessel
A
N Give-way
Vessel
D
Meeting One Short Blast
Situation Port to Port
R
U Give-way
L Vessel
E
Give-way
S Vessel
182. Crossing Situation
I One Short Blast
N Port to Port
L
A In inland waters,
N starboard-to-
starboard passing
D
is authorized only
if ships are not
R meeting end-on
U and safe passage
L is assured
E without any
S maneuvering.