NAVIGATION (COLLISION) REGULATIONS 1983 - SCHEDULE 1

SCHEDULE 1 International regulations for preventing collisions at sea

(Clause 3)

Part A General

Rule 1 Application

(a) These Rules shall apply to all vessels upon the high seas and in all
waters connected therewith navigable by seagoing vessels.

(b) Nothing in these Rules shall interfere with the operation of special rules
made by an appropriate authority for roadsteads, harbours, rivers, lakes or
inland waterways connected with the high seas and navigable by seagoing
vessels. Such special rules shall conform as closely as possible to these
Rules.

(c) Nothing in these Rules shall interfere with the operation of any special
rules made by the Government of any State with respect to additional station
or signal lights, shapes or whistle signals for ships of war and vessels
proceeding under convoy, or with respect to additional station or signal
lights or shapes for fishing vessels engaged in fishing as a fleet. These
additional station or signal lights, shapes or whistle signals shall, so far
as possible, be such that they cannot be mistaken for any light, shape or
signal authorized elsewhere under these Rules.

(d) Traffic separation schemes may be adopted by the Organization for the
purpose of these Rules.

(e) Whenever the Government concerned shall have determined that a vessel of
special construction or purpose cannot comply fully with the provisions of any
of these Rules with respect to the number, position, range or arc of
visibility of lights or shapes, as well as to the disposition and
characteristics of sound-signalling appliances, such vessel shall comply with
such other provisions in regard to the number, position, range or arc of
visibility of lights or shapes, as well as to the disposition and
characteristics of sound-signalling appliances, as her Government shall have
determined to be the closest possible compliance with these Rules in respect
of that vessel.

Rule 2 Responsibility

(a) Nothing in these Rules shall exonerate any vessel, or the owner, master or
crew thereof, from the consequences of any neglect to comply with these Rules
or of the neglect of any precaution which may be required by the ordinary
practice of seamen, or by the special circumstances of the case.

(b) In construing and complying with these Rules due regard shall be had to
all dangers of navigation and collision and to any special circumstances,
including the limitations of the vessels involved, which may make a departure
from these Rules necessary to avoid immediate danger.

Rule 3 General definitions

For the purpose of these Rules, except where the context otherwise requires:

(a) The word vessel includes every description of water craft, including
non-displacement craft and seaplanes, used or capable of being used as a means
of transportation on water.

(b) The term power-driven vessel means any vessel propelled by machinery.

(c) The term sailing vessel means any vessel under sail provided that
propelling machinery, if fitted, is not being used.

(d) The term vessel engaged in fishing means any vessel fishing with nets,
lines, trawls or other fishing apparatus which restrict manoeuvrability, but
does not include a vessel fishing with trolling lines or other fishing
apparatus which do not restrict manoeuvrability.

(e) The word seaplane includes any aircraft designed to manoeuvre on the
water.

(f) The term vessel not under command means a vessel which through some
exceptional circumstance is unable to manoeuvre as required by these Rules and
is therefore unable to keep out of the way of another vessel.

(g) The term vessel restricted in her ability to manoeuvre means a vessel
which from the nature of her work is restricted in her ability to manoeuvre as
required by these Rules and is therefore unable to keep out of the way of
another vessel.

The term vessels restricted in their ability to manoeuvre shall include but
not be limited to:

(i) a vessel engaged in laying, servicing or picking up a navigation mark,
submarine cable or pipeline,

(ii) a vessel engaged in dredging, surveying or underwater operations,

(iii) a vessel engaged in replenishment or transferring persons, provisions or
cargo while underway,

(iv) a vessel engaged in the launching or recovery of aircraft,

(v) a vessel engaged in mineclearance operations,

(vi) a vessel engaged in a towing operation such as severely restricts the
towing vessel and her tow in their ability to deviate from their course.

(h) The term vessel constrained by her draught means a power-driven vessel
which because of her draught in relation to the available depth and width of
navigable water is severely restricted in her ability to deviate from the
course she is following.

(i) The word underway means a vessel that is not at anchor, or made fast to
the shore, or aground.

(j) The words length and breadth of a vessel mean her length overall and
greatest breadth.

(k) Vessels shall be deemed to be in sight of one another only when one can be
observed visually from the other.

(l) The term restricted visibility means any condition in which visibility is
restricted by fog, mist, falling snow, heavy rainstorms, sandstorms or any
other similar causes.

Part B Steering and sailing rules

Section I Conduct of vessels in any condition of visibility

Rule 4 Application

Rules in this Section apply in any condition of visibility.

Rule 5 Look-out

Every vessel shall at all times maintain a proper look-out by sight and
hearing as well as by all available means appropriate in the prevailing
circumstances and conditions so as to make a full appraisal of the situation
and of the risk of collision.

Rule 6 Safe speed

Every vessel shall at all times proceed at a safe speed so that she can take
proper and effective action to avoid collision and be stopped within a
distance appropriate to the prevailing circumstances and conditions.

In determining a safe speed the following factors shall be among those taken
into account:

(a) By all vessels:

(i) the state of visibility,

(ii) the traffic density including concentrations of fishing vessels or any
other vessels,

(iii) the manoeuvrability of the vessel with special reference to stopping
distance and turning ability in the prevailing conditions,

(iv) at night the presence of background light such as from shore lights or
from back scatter of her own lights,

(v) the state of wind, sea and current, and the proximity of navigational
hazards,

(vi) the draught in relation to the available depth of water.

(b) Additionally, by vessels with operational radar:

(i) the characteristics, efficiency and limitations of the radar equipment,

(ii) any constraints imposed by the radar range scale in use,

(iii) the effect on radar detection of the sea state, weather and other
sources of interference,

(iv) the possibility that small vessels, ice and other floating objects may
not be detected by radar at an adequate range,

(v) the number, location and movement of vessels detected by radar,

(vi) the more exact assessment of the visibility that may be possible when
radar is used to determine the range of vessels or other objects in the
vicinity.

Rule 7 Risk of collision

(a) Every vessel shall use all available means appropriate to the prevailing
circumstances and conditions to determine if risk of collision exists. If
there is any doubt such risk shall be deemed to exist.

(b) Proper use shall be made of radar equipment if fitted and operational,
including long-range scanning to obtain early warning of risk of collision and
radar plotting or equivalent systematic observation of detected objects.

(c) Assumptions shall not be made on the basis of scanty information,
especially scanty radar information.

(d) In determining if risk of collision exists the following considerations
shall be among those taken into account:

(i) such risk shall be deemed to exist if the compass bearing of an
approaching vessel does not appreciably change,

(ii) such risk may sometimes exist even when an appreciable bearing change is
evident, particularly when approaching a very large vessel or a tow or when
approaching a vessel at close range.

Rule 8 Action to avoid collision

(a) Any action taken to avoid collision shall, if the circumstances of the
case admit, be positive, made in ample time and with due regard to the
observance of good seamanship.

(b) Any alteration of course and/or speed to avoid collision shall, if the
circumstances of the case admit, be large enough to be readily apparent to
another vessel observing visually or by radar; a succession of small
alterations of course and/or speed should be avoided.

(c) If there is sufficient sea room, alteration of course alone may be the
most effective action to avoid a close-quarters situation provided that it is
made in good time, is substantial and does not result in another
close-quarters situation.

(d) Action taken to avoid collision with another vessel shall be such as to
result in passing at a safe distance. The effectiveness of the action shall be
carefully checked until the other vessel is finally past and clear.

(e) If necessary to avoid collision or allow more time to assess the
situation, a vessel shall slacken her speed or take all way off by stopping or
reversing her means of propulsion.

(f) (i) A vessel which, by any of these Rules, is required not to impede the
passage or safe passage of another vessel shall, when required by the
circumstances of the case, take early action to allow sufficient sea room for
the safe passage of the other vessel.

(ii) A vessel required not to impede the passage or safe passage of another
vessel is not relieved of this obligation if approaching the other vessel so
as to involve risk of collision and shall, when taking action, have full
regard to the action which may be required by the Rules of this Part.

(iii) A vessel the passage of which is not to be impeded remains fully obliged
to comply with the Rules of this Part when the two vessels are approaching one
another so as to involve risk of collision.

Rule 9 Narrow channels

(a) A vessel proceeding along the course of a narrow channel or fairway shall
keep as near to the outer limit of the channel or fairway which lines on her
starboard side as is safe and practicable.

(b) A vessel of less than 20 metres in length or a sailing vessel shall not
impede the passage of a vessel which can safely navigate only within a narrow
channel or fairway.

(c) A vessel engaged in fishing shall not impede the passage of any other
vessel navigating within a narrow channel or fairway.

(d) A vessel shall not cross a narrow channel or fairway if such crossing
impedes the passage of a vessel which can safely navigate only within such
channel or fairway. The latter vessel may use the sound signal prescribed in
Rule 34 (d) if in doubt as to the intention of the crossing vessel.

(e) (i) In a narrow channel or fairway when overtaking can take place only if
the vessel to be overtaken has to take action to permit safe passing, the
vessel intending to overtake shall indicate her intention by sounding the
appropriate signal prescribed in Rule 34 (c) (i). The vessel to be overtaken
shall, if in agreement, sound the appropriate signal prescribed in Rule 34 (c)
(ii) and take steps to permit safe passing. If in doubt she may sound the
signals prescribed in Rule 34 (d).

(ii) This Rule does not relieve the overtaking vessel of her obligation under
Rule 13.

(f) A vessel nearing a bend or an area of a narrow channel or fairway where
other vessels may be obscured by an intervening obstruction shall navigate
with particular alertness and caution and shall sound the appropriate signal
prescribed in Rule 34 (e).

(g) Any vessel shall, if the circumstances of the case admit, avoid anchoring
in a narrow channel.

Rule 10 Traffic separation schemes

(a) This Rule applies to traffic separation schemes adopted by the
Organization and does not relieve any vessel of her obligation under any other
Rule.

(b) A vessel using a traffic separation scheme shall:

(i) proceed in the appropriate traffic lane in the general direction of
traffic flow for that lane,

(ii) so far as practicable keep clear of a traffic separation line or
separation zone,

(iii) normally join or leave a traffic lane at the termination of the lane,
but when joining or leaving from either side shall do so at as small an angle
to the general direction of traffic flow as practicable.

(c) A vessel shall, so far as practicable, avoid crossing traffic lanes but if
obliged to do so shall cross on a heading as nearly as practicable at right
angles to the general direction of the traffic flow.

(d) Inshore traffic zones shall not normally be used by through traffic which
can safely use the appropriate traffic lane within the adjacent traffic
separation scheme. However, vessels of less than 20 metres in length and
sailing vessels may under all circumstances use inshore traffic zones.

(e) A vessel, other than a crossing vessel or a vessel joining or leaving a
lane shall not normally enter a separation zone or cross a separation line
except:

(i) in cases of emergency to avoid immediate danger,

(ii) to engage in fishing within a separation zone.

(f) A vessel navigating in areas near the terminations of traffic separation
schemes shall do so with particular caution.

(g) A vessel shall so far as practicable avoid anchoring in a traffic
separation scheme or in areas near its terminations.

(h) A vessel not using a traffic separation scheme shall avoid it by as wide a
margin as is practicable.

(i) A vessel engaged in fishing shall not impede the passage of any vessel
following a traffic lane.

(j) A vessel of less than 20 metres in length or a sailing vessel shall not
impede the safe passage of a power-driven vessel following a traffic lane.

(k) A vessel restricted in her ability to manoeuvre when engaged in an
operation for the maintenance of safety of navigation in a traffic separation
scheme is exempted from complying with this Rule to the extent necessary to
carry out the operation.

(l) A vessel restricted in her ability to manoeuvre when engaged in an
operation for the laying, servicing or picking up of a submarine cable, within
a traffic separation scheme, is exempted from complying with this Rule to the
extent necessary to carry out the operation.

Section II Conduct of vessels in sight of one another

Rule 11 Application

Rules in this Section shall apply to vessels in sight of one another.

Rule 12 Sailing vessels

(a) When two sailing vessels are approaching one another, so as to involve
risk of collision, one of them shall keep out of the way of the other as
follows:

(i) when each has the wind on a different side, the vessel which has the wind
on the port side shall keep out of the way of the other,

(ii) when both have the wind on the same side, the vessel which is to windward
shall keep out of the way of the vessel which is to leeward,

(iii) if a vessel with the wind on the port side sees a vessel to windward and
cannot determine with certainty whether the other vessel has the wind on the
port or on the starboard side, she shall keep out of the way of the other.

(b) For the purposes of this Rule the windward side shall be deemed to be the
side opposite to that on which the mainsail is carried or, in the case of a
square-rigged vessel, the side opposite to that on which the largest
fore-and-aft sail is carried.

Rule 13 Overtaking

(a) Notwithstanding anything contained in the Rules of Part B, Sections I and
II any vessel overtaking any other shall keep out of the way of the vessel
being overtaken.

(b) A vessel shall be deemed to be overtaking when coming up with another
vessel from a direction more than 22.5 degrees abaft her beam, that is, in
such a position with reference to the vessel she is overtaking, that at night
she would be able to see only the sternlight of that vessel but neither of her
sidelights.

(c) When a vessel is in any doubt as to whether she is overtaking another, she
shall assume that this is the case and act accordingly.

(d) Any subsequent alteration of the bearing between the two vessels shall not
make the overtaking vessel a crossing vessel within the meaning of these Rules
or relieve her of the duty of keeping clear of the overtaken vessel until she
is finally past and clear.

Rule 14 Head-on situation

(a) When two power-driven vessels are meeting on reciprocal or nearly
reciprocal courses so as to involve risk of collision each shall alter her
course to starboard so that each shall pass on the port side of the other.

(b) Such a situation shall be deemed to exist when a vessel sees the other
ahead or nearly ahead and by night she could see the masthead lights of the
other in a line or nearly in a line and/or both sidelights and by day she
observes the corresponding aspect of the other vessel.

(c) When a vessel is in any doubt as to whether such a situation exists she
shall assume that it does exist and act accordingly.

Rule 15 Crossing situation

When two power-driven vessels are crossing so as to involve risk of collision,
the vessel which has the other on her own starboard side shall keep out of the
way and shall, if the circumstances of the case admit, avoid crossing ahead of
the other vessel.

Rule 16 Action by give-way vessel

Every vessel which is directed to keep out of the way of another vessel shall,
so far as possible, take early and substantial action to keep well clear.

Rule 17 Action by stand-on vessel

(a) (i) Where one of two vessels is to keep out of the way the other shall
keep her course and speed.

(ii) The latter vessel may however take action to avoid collision by her
manoeuvre alone, as soon as it becomes apparent to her that the vessel
required to keep out of the way is not taking appropriate action in compliance
with these Rules.

(b) When, from any cause, the vessel required to keep her course and speed
finds herself so close that collision cannot be avoided by the action of the
give-way vessel alone, she shall take such action as will best aid to avoid
collision.

(c) A power-driven vessel which takes action in a crossing situation in
accordance with subparagraph (a) (ii) of this Rule to avoid collision with
another power-driven vessel shall, if the circumstances of the case admit, not
alter course to port for a vessel on her own port side.

(d) This Rule does not relieve the give-way vessel of her obligation to keep
out of the way.

Rule 18 Responsibilities between vessels

Except where Rules 9, 10 and 13 otherwise require:

(a) A power-driven vessel underway shall keep out of the way of:

(i) a vessel not under command,

(ii) a vessel restricted in her ability to manoeuvre,

(iii) a vessel engaged in fishing,

(iv) a sailing vessel.

(b) A sailing vessel underway shall keep out of the way of:

(i) a vessel not under command,

(ii) a vessel restricted in her ability to manoeuvre,

(iii) a vessel engaged in fishing.

(c) A vessel engaged in fishing when underway shall, so far as possible, keep
out of the way of:

(i) a vessel not under command,

(ii) a vessel restricted in her ability to manoeuvre.

(d) (i) Any vessel other than a vessel not under command or a vessel
restricted in her ability to manoeuvre shall, if the circumstances of the case
admit, avoid impeding the safe passage of a vessel constrained by her draught,
exhibiting the signals in Rule 28.

(ii) A vessel constrained by her draught shall navigate with particular
caution having full regard to her special condition.

(e) A seaplane on the water shall, in general, keep well clear of all vessels
and avoid impeding their navigation. In circumstances, however, where risk of
collision exists, she shall comply with the Rules of this Part.

Section III Conduct of vessels in restricted visibility

Rule 19 Conduct of vessels in restricted visibility

(a) This Rule applies to vessels not in sight of one another when navigating
in or near an area of restricted visibility.

(b) Every vessel shall proceed at a safe speed adapted to the prevailing
circumstances and conditions of restricted visibility. A power-driven vessel
shall have her engines ready for immediate manoeuvre.

(c) Every vessel shall have due regard to the prevailing circumstances and
conditions of restricted visibility when complying with the Rules of Section I
of this Part.

(d) A vessel which detects by radar alone the presence of another vessel shall
determine if a close-quarters situation is developing and/or risk of collision
exists. If so, she shall take avoiding action in ample time, provided that
when such action consists of an alteration of course, so far as possible the
following shall be avoided:

(i) an alteration of course to port for a vessel forward of the beam, other
than for a vessel being overtaken,

(ii) an alteration of course towards a vessel abeam or abaft the beam.

(e) Except where it has been determined that a risk of collision does not
exist, every vessel which hears apparently forward of her beam the fog signal
of another vessel, or which cannot avoid a close-quarters situation with
another vessel forward of her beam, shall reduce her speed to the minimum at
which she can be kept on her course. She shall if necessary take all her way
off and in any event navigate with extreme caution until danger of collision
is over.

Part C Lights and shapes

Rule 20 Application

(a) Rules in this Part shall be complied with in all weathers.

(b) The Rules concerning lights shall be complied with from sunset to sunrise,
and during such times no other lights shall be exhibited, except such lights
as cannot be mistaken for the lights specified in these Rules or do not impair
their visibility or distinctive character, or interfere with the keeping of a
proper look-out.

(c) The lights prescribed by these Rules shall, if carried, also be exhibited
from sunrise to sunset in restricted visibility and may be exhibited in all
other circumstances when it is deemed necessary.

(d) The Rules concerning shapes shall be complied with by day.

(e) The lights and shapes specified in these Rules shall comply with the
provisions of Annex I to these Regulations.

Rule 21 Definitions

(a) Masthead light means a white light placed over the fore and aft centreline
of the vessel showing an unbroken light over an arc of the horizon of 225
degrees and so fixed as to show the light from right ahead to 22.5 degrees
abaft the beam on either side of the vessel.

(b) Sidelights means a green light on the starboard side and a red light on
the port side each showing an unbroken light over an arc of the horizon of
112.5 degrees and so fixed as to show the light from right ahead to 22.5
degrees abaft the beam on its respective side. In a vessel of less than 20
metres in length the sidelights may be combined in one lantern carried on the
fore and aft centreline of the vessel.

(c) Sternlight means a white light placed as nearly as practicable at the
stern showing an unbroken light over an arc of the horizon of 135 degrees and
so fixed as to show the light 67.5 degrees from right aft on each side of the
vessel.

(d) Towing light means a yellow light having the same characteristics as the
sternlight defined in paragraph (c) of this Rule.

(e) All round light means a light showing an unbroken light over an arc of the
horizon of 360 degrees.

(f) Flashing light means a light flashing at regular intervals at a frequency
of 120 flashes or more per minute.

Rule 22 Visibility of lights

The lights prescribed in these Rules shall have an intensity as specified in
Section 8 of Annex I to these Regulations so as to be visible at the following
minimum ranges:

(a) In vessels of 50 metres or more in length:

a masthead light, 6 miles,

a sidelight, 3 miles,

a sternlight, 3 miles,

a towing light, 3 miles,

a white, red, green or yellow all-round light, 3 miles.

(b) In vessels of 12 metres or more in length but less than 50 metres in
length:

a masthead light, 5 miles; except that where the length of the vessel is less
than 20 metres, 3 miles,

a sidelight, 2 miles,

a sternlight, 2 miles,

a towing light, 2 miles,

a white, red, green or yellow all-round light, 2 miles.

(c) In vessels of less than 12 metres in length:

a masthead light, 2 miles,

a sidelight, 1 mile,

a sternlight, 2 miles,

a towing light, 2 miles,

a white, red, green or yellow all-round light, 2 miles.

(d) In inconspicuous, partly submerged vessels or objects being towed:

a white all-round light, 3 miles.

Rule 23 Power-driven vessels underway

(a) A power-driven vessel underway shall exhibit:

(i) a masthead light forward,

(ii) a second masthead light abaft of and higher than the forward one; except
that a vessel of less than 50 metres in length shall not be obliged to exhibit
such light and may do so,

(iii) sidelights,

(iv) a sternlight.

(b) An air-cushion vessel when operating in the non-displacement mode shall,
in addition to the lights prescribed in paragraph (a) of this Rule exhibit an
all-round flashing yellow light.

(c) (i) A power-driven vessel of less than 12 metres in length may in lieu of
the lights prescribed in paragraph (a) of this Rule exhibit an all-round white
light and sidelights,

(ii) a power-driven vessel of less than 7 metres in length whose maximum speed
does not exceed 7 knots may in lieu of the lights prescribed in paragraph (a)
of this Rule exhibit an all-round white light and shall, if practicable, also
exhibit sidelights,

(iii) the masthead light of all-round white light on a power-driven vessel of
less than 12 metres in length may be displayed from the fore and aft
centreline of the vessel if centreline fitting is not practicable, provided
that the sidelights are combined in one lantern which shall be carried on the
fore and aft centreline of the vessel or located as nearly as practicable in
the same fore and aft line as the masthead light or the all-round white light.

Rule 24 Towing and pushing

(a) A power-driven vessel when towing shall exhibit:

(i) instead of the light prescribed in Rule 23 (a) (i) or (a) (ii), two
masthead lights in a vertical line. When the length of the tow, measuring from
the stern of the towing vessel to the after end of the tow exceeds 200 metres,
three such lights in a vertical line,

(ii) sidelights,

(iii) a sternlight,

(iv) a towing light in a vertical line above the sternlight,

(v) when the length of the tow exceeds 200 metres, a diamond shape where it
can best be seen.

(b) When a pushing vessel and a vessel being pushed ahead are rigidly
connected in a composite unit they shall be regarded as a power-driven vessel
and exhibit the lights prescribed in Rule 23.

(c) A power-driven vessel when pushing ahead or towing alongside, except in
the case of a composite unit, shall exhibit:

(i) instead of the light prescribed in Rule 23 (a) (i) or (a) (ii), two
masthead lights in a vertical line,

(ii) sidelights,

(iii) a sternlight.

(d) A power-driven vessel to which paragraph (a) or (c) of this Rule apply
shall also comply with Rule 23 (a) (ii).

(e) A vessel or object being towed, other than those mentioned in paragraph
(g) of this Rule, shall exhibit:

(i) sidelights,

(ii) a sternlight,

(iii) where the length of the tow exceeds 200 metres, a diamond shape where it
can best be seen.

(f) Provided that any number of vessels being towed alongside or pushed in a
group shall be lighted as one vessel:

(i) a vessel being pushed ahead, not being part of a composite unit, shall
exhibit at the forward end, sidelights,

(ii) a vessel being towed alongside shall exhibit a sternlight and at the
forward end, sidelights.

(g) An inconspicuous, partly submerged vessel or object, or combination of
such vessels or objects being towed, shall exhibit:

(i) if it *less than 25 metres in breadth, one all-round white light at or
near the forward end and one at or near the after end except that dracones
need not exhibit a lights* at or near the forward end,

(ii) if it is 25 metres or more in breadth, two additional all-round white
lights at or near the extremities of its breadth,

(iii) if it exceeds 100 metres in length, additional all-round white lights
between the lights prescribed in sub-paragraphs (i) and (ii) so that the
distance between the lights shall not exceed 100 metres,

(iv) a diamond shape at or near the aftermost extremity of the last vessel or
object being towed and if the length of the tow exceeds 200 metres an
additional diamond shape where it can best be seen and located as far forward
as is practicable.

(h) Where from any sufficient cause it is impracticable for a vessel or object
being towed to exhibit the lights or shapes prescribed in paragraph (e) or (g)
of his* Rule, all possible measures shall be taken to light the vessel or
object towed or at least to indicate the presence of such vessel or object.

(i) Where from any sufficient cause it is impracticable for a vessel not
normally engaged in towing operations to display the lights prescribed in
paragraph (a) or (c) of this Rule, such vessel shall not be required to
exhibit those lights when engaged in towing another vessel in distress or
otherwise in need of assistance. All possible measures shall be taken to
indicate the nature of the relationship between the towing vessel and the
vessel being towed as authorizd* by Rule 36, in particular by illuminating the
towline.

*Sic.

Rule 25 Sailing vessels underway and vessels under oars

(a) A sailing vessel underway shall exhibit:

(i) sidelights,

(ii) a sternlight.

(b) In a sailing vessel of less than 20 metres in length the lights the
lights* prescribed in paragraph (a) of this Rule may be combined in one
lantern carried at or near the top of the mast where it can best be seen.

*Sic.

(c) A sailing vessel underway may, in addition to the lights prescribed in
paragraph (a) of this Rule, exhibit at or near the top of the mast, where they
can best be seen, two all-round lights in a vertical line, the upper being red
and the lower green, but these lights shall not be exhibited in conjunction
with the combined lantern permitted by paragraph (b) of this Rule.

(d) (i) A sailing vessel of less than 7 metres in length shall, if
practicable, exhibit the lights prescribed in paragraph (a) or (b) of this
Rule, but if she does not, she shall have ready at hand an electric torch or
lighted lantern showing a white light which shall be exhibited in sufficient
time to prevent collision.

(ii) A vessel under oars may exhibit the lights prescribed in this Rule for
sailing vessels, but if she does not, she shall have ready at hand an electric
torch or lighted lantern showing a white light which shall be exhibited in
sufficient time to prevent collision.

(e) A vessel proceeding under sail when also being propelled by machinery
shall exhibit forward where it can best be seen a conical shape, apex
downwards.

Rule 26 Fishing vessels

(a) A vessel engaged in fishing, whether underway or at anchor, shall exhibit
only the lights and shapes prescribed in this Rule.

(b) A vessel when engaged in trawling, by which is meant the dragging through
the water of a dredge net or other apparatus used as a fishing appliance,
shall exhibit:

(i) two all-round lights in a vertical line, the upper being green and the
lower white, or a shape consisting of two cones with their apexes together in
a vertical line one above the other; a vessel of less than 20 metres in length
may instead of this shape exhibit a basket,

(ii) a masthead light abaft of and higher than the all-round green light; a
vessel of less than 50 metres in length shall not be obliged to exhibit such a
light but may do so,

(iii) when making way through the water, in addition to the lights prescribed
in this paragraph, sidelights and a sternlight.

(c) A vessel engaged in fishing, other than trawling, shall exhibit:

(i) two all-round lights in a vertical line, the upper being red and the lower
white, or a shape consisting of two cones with apexes together in a vertical
line one above the other; a vessel of less than 20 metres in length may
instead of this shape exhibit a basket,

(ii) when there is outlying gear extending more than 150 metres horizontally
from the vessel, an all-round white light or a cone apex upwards in the
direction of the gear,

(iii) when making way through the water, in addition to the lights prescribed
in this paragraph, sidelights and a sternlight.

(d) A vessel engaged in fishing in close proximity to other vessels engaged in
fishing may exhibit the additional signals described in Annex II to these
Regulations.

(e) A vessel when not engaged in fishing shall not exhibit the lights or
shapes prescribed in this Rule, but only those prescribed for a vessel of her
length.

Rule 27 Vessels not under command or restricted in their ability to manoeuvre

(a) A vessel not under command shall exhibit:

(i) two all-round red lights in a vertical line where they can best be seen,

(ii) two balls or similar shapes in a vertical line where they can best be
seen,

(iii) when making way through the water, in addition to the lights prescribed
in this paragraph, sidelights and a sternlight.

(b) A vessel restricted in her ability to manoeuvre, except a vessel engaged
in mine clearance operations, shall exhibit:

(i) three all-round lights in a vertical line where they can best be seen. The
highest and lowest of these lights shall be red and the middle light shall be
white,

(ii) three shapes in a vertical line where they can best be seen. The highest
and lowest of these shapes shall be balls and the middle one a diamond,

(iii) when making way through the water, a masthead light or lights,
sidelights and a sternlight, in addition to the lights prescribed in
sub-paragraph (i),

(iv) when at anchor, in addition to the lights or shapes prescribed in
sub-paragraphs (i) and (ii), the light, lights or shape prescribed in Rule 30.

(c) A power-driven vessel engaged in a towing operation such as severely
restricts the towing vessel and her tow in their ability to deviate from their
course shall, in addition to the lights or shapes prescribed in Rule 24 (a),
exhibit the lights or shapes prescribed in sub-paragraphs (b) (i) and (ii) of
this Rule.

(d) A vessel engaged in dredging or underwater operations, when restricted in
her ability to manoeuvre, shall exhibit the lights and shapes prescribed in
sub-paragraph (b) (i), (ii) and (iii) of this Rule and shall in addition, when
an obstruction exists, exhibit:

(i) two all-round red lights or two balls in a vertical line to indicate the
side on which the obstruction exists,

(ii) two all-round green lights or two diamonds in a vertical line to indicate
the side on which another vessel may pass,

(iii) when at anchor, the lights or shapes prescribed in this paragraph
instead of the lights or shape prescribed in Rule 30.

(e) Whenever the size of a vessel engaged in diving operations makes it
impracticable to exhibit all lights and shapes prescribed in paragraph (d) of
this Rule, the following shall be exhibited:

(i) three all-round lights in a vertical line where they can best be seen. The
highest and lowest of these lights shall be red and the middle light shall be
white,

(ii) a rigid replica of the International Code flag `A' not less than 1 metre
in height. Measures shall be taken to ensure its all-round visibility.

(f) A vessel engaged in mineclearance operations shall in addition to the
lights prescribed for a power-driven vessel in Rule 23 or to the lights or
shape prescribed for a vessel at anchor in Rule 30 as appropriate, exhibit
three all-round green lights or three balls. One of these lights or shapes
shall be exhibited near the foremast head and one at each end of the fore
yard. These lights or shapes indicate that it is dangerous for another vessel
to approach within 1 000 metres of the mineclearance vessel.

(g) Vessels of less than 12 metres in length, except those engaged in diving
operations, shall not be required to exhibit the lights and shapes prescribed
in this Rule.

(h) The signals prescribed in this Rule are not signals of vessels in distress
and requiring assistance. Such signals are contained in Annex IV to these
Regulations.

Rule 28 Vessels constrained by their draught

A vessel constrained by her draught may, in addition to the lights prescribed
for power-driven vessels in Rule 23, exhibit where they can best be seen three
all-round red lights in a vertical line, or a cylinder.

Rule 29 Pilot vessels

(a) A vessel engaged on pilotage duty shall exhibit:

(i) at or near the masthead, two all-round lights in a vertical line, the
upper being white and the lower red,

(ii) when underway, in addition, sidelights and a sternlight,

(iii) when at anchor, in addition to the lights prescribed in subparagraph
(i), the light, lights or shape prescribed in Rule 30 for vessels at anchor.

(b) A pilot vessel when not engaged on pilotage duty shall exhibit the lights
or shapes prescribed for a similar vessel of her length.

Rule 30 Anchored vessels and vessels aground

(a) A vessel at anchor shall exhibit where it can best be seen:

(i) in the fore part, an all-round white light or one ball,

(ii) at or near the stern and at a lower level than the light prescribed in
sub-paragraph (i), an all-round white light.

(b) A vessel of less than 50 metres in length may exhibit an all-round white
light where it can best be seen instead of the lights prescribed in paragraph
(a) of this Rule.

(c) A vessel at anchor may, and a vessel of 100 metres and more in length
shall, also use the available working or equivalent lights to illuminate her
decks.

(d) A vessel aground shall exhibit the lights prescribed in paragraph (a) or
(b) of this Rule and in addition, where they can best be seen:

(i) two all-round red lights in a vertical line,

(ii) three balls in a vertical line.

(e) A vessel of less than 7 metres in length, when an* anchor not in or near a
narrow channel, fairway or anchorage, or where other vessels normally
navigate, shall not be required to exhibit the lights or shape prescribed in
paragraphs (a) and (b) of this Rule.

*Sic.

(f) A vessel of less than 12 metres in length, when aground, shall not be
required to exhibit the lights or shapes prescribed in sub-paragraphs (d) (i)
and (ii) of this Rule.

Rule 31 Seaplanes

Where it is impracticable for a seaplane to exhibit lights and shapes of the
characteristics or in the positions prescribed in the Rules of this Part she
shall exhibit lights and shapes as closely similar in characteristics and
position as is possible.

Part D Sound and light signals

Rule 32 Definitions

(a) The word whistle means any sound signalling appliance capable of producing
the prescribed blasts and which complies with the specifications in Annex III
to these Regulations.

(b) The term short blast means a blast of about one second's duration.

(c) The term prolonged blast means a blast of from four to six seconds'
duration.

Rule 33 Equipment for sound signals

(a) A vessel of 12 metres or more in length shall be provided with a whistle
and a bell and a vessel of 100 metres or more in length shall, in addition, be
provided with a gong, the tone and sound of which cannot be confused with that
of the bell. The whistle, bell and gong shall comply with the specifications
in Annex III to these Regulations. The bell or gong or both may be replaced by
other equipment having the same respective sound characteristics, provided
that manual sounding of the prescribed signals shall always be possible.

(b) A vessel of less than 12 metres in length shall not be obliged to carry
the sound signalling appliances prescribed in paragraph (a) of this Rule but
if she does not, she shall be provided with some other means of making an
efficient sound signal.

Rule 34 Manoeuvring and warning signals

(a) When vessels are in sight of one another, a power-driven vessel underway,
when manoeuvring as authorized or required by these Rules, shall indicate that
manoeuvre by the following signals on her whistle:

one short blast to mean `I am altering my course to starboard',

two short blasts to mean `I am altering my course to port',

three short blasts to mean `I am operating astern propulsion'.

(b) Any vessel may supplement the whistle signals prescribed in paragraph (a)
of this Rule by light signals, repeated as appropriate, whilst the manoeuvre
is being carried out:

(i) these light signals shall have the following significance:

one flash to mean `I am altering my course to staboard'*,

two flashes to mean `I am altering my course to port',

three flashes to mean `I am operating astern propulsion',

*Sic.

(ii) the duration of each flash shall be about one second, the interval
between flashes shall be about one second, and the interval between successive
signals shall be not less than ten seconds,

(iii) the light used for this signal shall, if fitted, be an all-round white
light, visible at a minimum range of 5 miles, and shall comply with the
provisions of Annex I to these Regulations.

(c) When in sight of one another in a narrow channel or fairway:

(i) a vessel intending to overtake another shall in compliance with Rule 9 (e)
(i) indicate her intention by the following signals on her whistle:

two prolonged blasts followed by one short blast to mean `I intend to overtake
you on your starboard side',

two prolonged blasts followed by two short blasts to mean `I intend to
overtake you on your port side',

(ii) the vessel about to be overtaken when acting in accordance with Rule 9
(e) (i) shall indicate her agreement by the following signal on her whistle:

one prolonged, one short, one prolonged and one short blast, in that order.

(d) When vessels in sight of one another are approaching each other and from
any cause either vessel fails to understand the intentions or actions of the
other, or is in doubt whether sufficient action is being taken by the other to
avoid collision, the vessel in doubt shall immediately indicate such doubt by
giving at least five short and rapid blasts on the whistle. Such signal may be
supplemented by a light signal of at least five short and rapid flashes.

(e) A vessel nearing a bend or an area of a channel or fairway where other
vessels may be obscured by an intervening obstruction shall sound one
prolonged blast. Such signal shall be answered with a prolonged blast by any
approaching vessel that may be within hearing around the bend or behind the
intervening obstruction.

(f) If whistles are fitted on a vessel at a distance apart of more than 100
metres, one whistle only shall be used for giving manoeuvring and warning
signals.

Rule 35 Sound signals in restricted visibility

In or near an area of restricted visibility, whether by day or night, the
signals prescribed in this Rule shall be used as follows:

(a) A power-driven vessel making way through the water shall sound at
intervals of not more than 2 minutes one prolonged blast.

(b) A power-driven vessel underway but stopped and making no way through the
water shall sound at intervals of not more than 2 minutes two prolonged blasts
in succession with an interval of about 2 seconds between them.

(c) A vessel not under command, a vessel restricted in her ability to
manoeuvre, a vessel constrained by her draught, a sailing vessel, a vessel
engaged in fishing and a vessel engaged in towing or pushing another vessel
shall, instead of the signals prescribed in paragraphs (a) or (b) of this
Rule, sound at intervals of not more than 2 minutes three blasts in
succession, namely one prolonged followed by two short blasts.

(d) A vessel engaged in fishing, when at anchor, and a vessel restricted in
her ability to manoeuvre when carrying out her work at anchor, shall instead
of the signals prescribed in paragraph (g) of this Rule sound the signal
prescribed in paragraph (c) of this Rule.

(e) A vessel towed or if more than one vessel is towed the last vessel of the
tow, if manned, shall at intervals of not more than 2 minutes sound four
blasts in succession, namely one prolonged followed by three short blasts.
When practicable, this signal shall be made immediately after the signal made
by the towing vessel.

(f) When a pushing vessel and a vessel being pushed ahead are rigidly
connected in a composite unit they shall be regarded as a power-driven vessel
and shall give the signals prescribed in paragraphs (a) or (b) of this Rule.

(g) A vessel at anchor shall at intervals of not more than one minute ring the
bell rapidly for about 5 seconds. In a vessel of 100 metres or more in length
the bell shall be sounded in the forepart of the vessel and immediately after
the ringing of the bell the gong shall be sounded rapidly for about 5 seconds
in the after part of the vessel. A vessel at anchor may in addition sound
three blasts in succession, namely one short, one prolonged and one short
blast, to give warning of her position and of the possibility of collision to
an approaching vessel.

(h) A vessel aground shall give the bell signal and if required the gong
signal prescribed in paragraph (g) of this Rule and shall, in addition, give
three separate and distinct strokes on the bell immediately before and after
the rapid ringing of the bell. A vessel aground may in addition sound an
appropriate whistle signal.

(i) A vessel of less than 12 metres in length shall not be obliged to give the
above-mentioned signals but, if she does not, shall make some other efficient
sound signal at intervals of not more than 2 minutes.

(j) A pilot vessel when engaged on pilotage duty may in addition to the
signals prescribed in paragraphs (a), (b) or (g) of this Rule sound an
identity signal consisting of four short blasts.

Rule 36 Signals to attract attention

If necessary to attract the attention of another vessel any vessel may make
light or sound signals that cannot be mistaken for any signal authorized
elsewhere in these Rules, or may direct the beam of her searchlight in the
direction of the danger, in such a way as not to embarrass any vessel. Any
light to attract the attention of another vessel shall be such that it cannot
be mistaken for any aid to navigation. For the purpose of this Rule the use of
high intensity intermittent or revolving lights, such as strobe lights, shall
be avoided.

Rule 37 Distress signals

When a vessel is in distress and requires assistance she shall use or exhibit
the signals described in Annex IV to these Regulations.

Part E Exemptions

Rule 38 Exemptions

Any vessel (or class of vessels) provided that she complies with the
requirements of the International Regulations for Preventing Collisions at
Sea, 1960, the keel of which is laid or which is at a corresponding stage of
construction before the entry into force of these Regulations may be exempted
from compliance therewith as follows:

(a) The installation of lights with ranges prescribed in Rule 22, until four
years after the date of entry into force of these Regulations.

(b) The installation of lights with colour specifications as prescribed in
Section 7 of Annex I to these Regulations, until four years after the date of
entry into force of these Regulations.

(c) The repositioning of lights as a result of conversion from Imperial to
metric units and rounding off measurement figures, permanent exemption.

(d) (i) The repositioning of masthead lights on vessels of less than 150
metres in length, resulting from the prescriptions of Section 3 (a) of Annex
I, to these Regulations, permanent exemption.

(ii) The repositioning of masthead lights on vessels of 150 metres or more in
length, resulting from the prescriptions of Section 3 (a) of Annex I to these
Regulations, until nine years after the date of entry into force of these
Regulations.

(e) The repositioning of masthead lights resulting from the prescriptions of
Section 2 (b) of Annex I, to these Regulations until nine years after the date
of entry into force of these Regulations.

(f) The repositioning of sidelights resulting from the prescriptions of
Section 2 (g) and 3 (b) of Annex I, to these Regulations until nine years
after the date of entry into force of these Regulations.

(g) The requirements for sound signal appliances prescribed in Annex III, to
these Regulations until nine years after the date of entry into force of these
Regulations.

(h) The repositioning of all-round lights resulting from the prescription of
Section 9 (b) of Annex I to these Regulations, permanent exemption.

Annex I Positioning and technical details of lights and shapes

_

1 Definition

The term height above the hull means height above the uppermost continuous
deck. This height shall be measured from the position vertically beneath the
location of the light.

_

2 Vertical positioning and spacing of lights

(a) On a power-driven vessel of 20 metres or more in length the masthead
lights shall be placed as follows:

(i) the forward masthead light, or if only one masthead light is carried, then
that light, at a height above the hull of not less than 6 metres, and, if the
breadth of the vessel exceeds 6 metres, then at a height above the hull not
less than such breadth, so however that the light need not be placed at a
greater height above the hull than 12 metres,

(ii) when two masthead lights are carried the after one shall be at least 4.5
metres vertically higher than the forward one.

(b) The vertical separation of masthead lights of power-driven vessels shall
be such that in all normal conditions of trim the after light will be seen
over and separate from the forward light at a distance of 1 000 metres from
the stem when viewed from sea level.

(c) The masthead light of a power-driven vessel of 12 metres but less than 20
metres in length shall be placed at a height above the gunwale of not less
than 2.5 metres.

(d) A power-driven vessel of less than 12 metres in length may carry the
uppermost light at a height of less than 2.5 metres above the gunwale. When
however a masthead light is carried in addition to sidelights and a sternlight
or the all-round light prescribed in Rule 23 (c) (i) is carried in addition to
sidelights, then such masthead light or all-round light shall be carried at
least 1 metre higher than the sidelights.

(e) One of the two or three masthead lights prescribed for a power-driven
vessel when engaged in towing or pushing another vessel shall be placed in the
same position as either the forward masthead light or the after masthead
light; provided that, if carried on the aftermast, the lowest after masthead
light shall be at least 4.5 metres vertically higher than the forward masthead
light.

(f) (i) The masthead light or lights prescribed in Rule 23 (a) shall be so
placed as to be above and clear of all other lights and obstructions except as
described in sub-paragraph (ii).

(ii) When it is impractible to carry the all-round lights prescribed by Rule
27 (b) (i) or Rule 28 below the masthead lights, they may be carried above the
after masthead light(s) or vertically in between the forward masthead light(s)
and after masthead light(s), provided that in the latter case the requirement
of Section 3 (c) of this Annex shall be complied with.

(g) The sidelights of a power-driven vessel shall be placed at a height above
the hull not greater than three quarters of that of the forward masthead
light. They shall not be so low as to be interfered with by deck lights.

(h) The sidelights, if in a combined lantern and carried on a power-driven
vessel of less than 20 metres in length, shall be placed not less than 1 metre
below the masthead light.

(i) When the Rules prescribe two or three lights to be carried in a vertical
line, they shall be spaced as follows:

(i) on a vessel of 20 metres in length or more such lights shall be spaced not
less than 2 metres apart, and the lowest of these lights shall, except where a
towing light is required, be placed at a height of not less than 4 metres
above the hull,

(ii) on a vessel of less than 20 metres in length such lights shall be spaced
not less than 1 metre apart and the lowest of these lights shall, except where
a towing light is required, be placed at a height of not less than 2 metres
above the gunwale,

(iii) when three lights are carried they shall be equally spaced.

(j) The lower of the two all-round lights prescribed for a vessel when engaged
in fishing shall be at a height above the sidelights not less than twice the
distance between the two vertical lights.

(k) The forward anchor light prescribed in Rule 30 (a) (i), when two are
carried, shall not be less than 4.5 metres above the after one. On a vessel of
50 metres or more in length this forward anchor light shall be placed at a
height of not less than 6 metres above the hull.

_

3 Horizontal positioning and spacing of lights

(a) When two masthead lights are prescribed for a power-driven vessel, the
horizontal distance between them shall not be less than one half of the length
of the vessel but need not be more than 100 metres. The forward light shall be
placed not more than one quarter of the length of the vessel from the stem.

(b) On a power-driven vessel of 20 metres or more in length the sidelights
shall not be placed in front of the forward masthead lights. They shall be
placed at or near the side of the vessel.

(c) When the lights prescribed in Rule 27 (b) (i) or Rule 28 are placed
vertically between the forward masthead light(s) and the after masthead
light(s) these all-round lights shall be placed at a horizontal distance of
not less than 2 metres from the fore and aft centreline of the vessel in the
athwartship direction.

_

4 Details of location of direction-indicating lights for fishing vessels,
dredges and vessels engaged in underwater operations

(a) The light indicating the direction of the outlying gear from a vessel
engaged in fishing as prescribed in Rule 26 (c) (ii) shall be placed at a
horizontal distance of not less than 2 metres and not more than 6 metres away
from the two all-round red and white lights. This light shall be placed not
higher than the all-round white light prescribed in Rule 26 (c) (i) and not
lower than the sidelights.

(b) The lights and shapes on a vessel engaged in dredging or underwater
operations to indicate the obstructed side and/or the side on which it is safe
to pass, as prescribed in Rule 27 (d) (i) and (ii), shall be placed at the
maximum practical horizontal distance, but in no case less than 2 metres, from
the lights or shapes prescribed in Rule 27 (b) (i) and (ii). In no case shall
the upper of these lights or shapes be at a greater height than the lower of
the three lights or shapes prescribed in Rule 27 (b) (i) and (ii).

_

5 Screens for sidelights

The sidelights of vessels of 20 metres or more in length shall be fitted with
inboard screens painted matt black, and meeting the requirements of Section 9
of this Annex. On vessels of less than 20 metres in length the sidelights, if
necessary to meet the requirements of Section 9 of this Annex, shall be fitted
with inboard matt black screens. With a combined lantern, using a single
vertical filament and a very narrow division between the green and red
sections, external screens need not be fitted.

_

6 Shapes

(a) Shapes shall be black and of the following sizes:

(i) a ball shall have a diameter of not less than 0.6 metre,

(ii) a cone shall have a base diameter of not less than 0.6 metre and a height
equal to its diameter,

(iii) a cylinder shall have a diameter of at least 0.6 metre and a height of
twice its diameter,

(iv) a diamond shape shall consist of two cones as defined in (ii) above
having a common base.

(b) The vertical distance between shapes shall be at least 1.5 metre.

(c) In a vessel of less than 20 metres in length shapes of lesser dimensions
but commensurate with the size of the vessel may be used and the distance
apart may be correspondingly reduced.

_

7 Colour specification of lights

The chromaticity of all navigation lights shall conform to the following
standards, which lie within the boundaries of the area of the diagram
specified for each colour by the International Commission on Illumination
(CIE).

The boundaries of the area for each colour are given by indicating the corner
co-ordinates, which are as follows:

(i) White

x 0.525 0.525 0.452 0.310 0.310 0.443

y 0.382 0.440 0.440 0.348 0.283 0.382

(ii) Green

x 0.028 0.009 0.300 0.203

y 0.385 0.723 0.511 0.356

(iii) Red

x 0.680 0.660 0.735 0.721

y 0.320 0.320 0.265 0.259

(iv) Yellow

x 0.612 0.618 0.575 0.575

y 0.382 0.382 0.425 0.406

_

8 Intensity of lights

(a) The minimum luminous intensity of lights shall be calculated by using the
formula:

[*Formula*]

I = 3.43 × 106 × T × D2 × K-D

where I is luminous intensity in candelas under service conditions,

[*Formula*]

T is threshold factor 2 × 10-7 lux,

D is range of visibility (luminous range) of the light in nautical miles,

K is atmospheric transmissivity.

For prescribed lights the value of K shall be 0.8, corresponding to a
meteorological visibility of approximately 13 nautical miles.

(b) A selection of figures derived from the formular* is given in the
following table:

*Sic.

Range of visibility (luminous range) of light in nautical miles Luminous
intensity

of light in candelas for

K = 0.8

D I

1

2

3

4

5

6 0.9

4.3

12

27

52

94

Note. The maximum luminous intensity of navigation lights should be limited to
avoid undue glare. This shall not be achieved by a variable control of the
luminous intensity.

_

9 Horizontal sectors

(a) (i) In the forward direction, sidelights as fitted on the vessel shall
show the minimum required intensities. The intensities must decrease to reach
practical cut-off between 1 degree and 3 degrees outside the prescribed
sectors.

(ii) For sternlights and masthead lights and at 22.5 degrees abaft the beam
for sidelights, the minimum required intensities shall be maintained over the
arc of the horizon up to 5 degrees within the limits of the sectors prescribed
in Rule 21. From 5 degrees within the prescribed sectors the intensity may
decrease by 50 per cent up to the prescribed limits; it shall decrease
steadily to reach practical cut-off at not more than 5 degrees outside the
prescribed sectors.

(b) All-round lights shall be so located as not to be obscured by masts,
topmasts or structures, within angular sectors of more than 6 degrees, except
anchor lights prescribed in Rule 30, which need not be placed at an
impracticable height above the hull.

_

10 Vertical sectors

(a) The vertical sectors of electric lights as fitted with the exception of
lights on sailing vessels underway shall ensure that:

(i) at least the required minimum intensity is maintained at all angles from 5
degrees above to 5 degrees below the horizontal,

(ii) at least 60 per cent of the required minimum intensity is maintained from
7.5 degrees above to 7.5 degrees below the horizontal.

(b) In the case of sailing vessels underway the vertical sectors of electric
lights as fitted shall ensure that:

(i) at least the required minimum intensity is maintained at all angles from 5
degrees above to 5 degrees below the horizontal,

(ii) at least 50 per cent of the required minimum intensity is maintained from
25 degrees above to 25 degrees below the horizontal.

(c) In the case of lights other than electric these specifications shall be
met as closely as possible.

_

11 Intensity of non-electric lights

Non-electric lights shall so far as practicable comply with the minimum
intensities, as specified in the Table given in Section 8 of this Annex.

_

12 Manoeuvring light

Notwithstanding the provisions of paragraph 2 (f) of this Annex the
manoeuvring light described in Rule 34 (b) shall be placed in the same fore
and aft vertical plane as the masthead light or lights and, where practicable,
at a minimum height of 2 metres vertically above the forward masthead light,
provided that it shall be carried not less than 2 metres vertically above or
below the after masthead light. On a vessel where only one masthead light is
carried the manoeuvring light, if fitted, shall be carried where it can best
be seen, not less than 2 metres vertically apart from the masthead light.

_

13 Approval

The construction of lights and shapes and the installation of lights on board
the vessel shall be to the satisfaction of the appropriate authority of the
State whose flag the vessel is entitled to fly.

Annex II Additional signals for fishing vessels fishing in close proximity

_

1 General

The lights mentioned herein shall, if exhibited in pursuance of Rule 26 (d),
be placed where they can best be seen. They shall be at least 0.9 metre apart
but at a lower level than lights prescribed in Rule 26 (b) (i) and (c) (i).
The lights shall be visible all round the horizon at a distance of at least 1
mile but at a lesser distance than the lights prescribed by these Rules for
fishing vessels.

_

2 Signals for trawlers

(a) Vessels when engaged in trawling, whether using demersal or pelagic gear,
may exhibit:

(i) when shooting their nets:

two white lights in a vertical line,

(ii) when hauling their nets:

one white light over one red light in a vertical line,

(iii) when the net has come fast upon an obstruction:

two red lights in a vertical line.

(b) Each vessel engaged in pair trawling may exhibit:

(i) by night, a searchlight directed forward and in the direction of the other
vessel of the pair,

(ii) when shooting or hauling their nets or when their nets have come fast
upon an obstruction, the lights prescribed in 2 (a) above.

_

3 Signal for purse seiners

Vessels engaged in fishing with purse seine gear may exhibit two yellow lights
in a vertical line. These lights shall flash alternately every second and with
equal light and occultation duration. These lights may be exhibited only when
the vessel is hampered by its fishing gear.

Annex III Technical details of sound signal appliances

_

1 Whistles

(a) Frequencies and range of audibility

The fundamental frequency of the signal shall lie within the range 70 700 Hz.

The range of audibility of the signal from a whistle shall be determined by
those frequencies, which may include the fundamental and/or one or more higher
frequencies, which lie within the range 180 700 Hz (+1 per cent) and which
provide the sound pressure levels specified in paragraph 1 (c) below.

(b) Limits of fundamental frequencies

To ensure a wide variety of whistle characteristics, the fundamental frequency
of a whistle shall be between the following limits:

(i) 70 200 Hz, for a vessel 200 metres or more in length,

(ii) 130 350 Hz, for a vessel 75 metres but less than 200 metres in length,

(iii) *250 700 Hz, for a vessel less than 75 metres in length.

*Sic.

(c) Sound signal intensity and range of audibility

A whistle fitted in a vessel shall provide, in the direction of maximum
intensity of the whistle and at a distance of 1 metre from it, a sound
pressure level in at least one 1/3-octave band within the range of frequencies
180 700 Hz (± 1 per cent) of not less than the appropriate figure given in the
table below:

Length of vessel in metres One/third octave band level at 1 metre in dB
referred to

2 × 10-5 N/m2 Audibility range in nautical miles

200 or more

75 but less than 200

20 but less than 75

Less than 20 143

138

130

120 2

1.5

1

0.5

The range of audibility in the table above is for information and is
approximately the range at which a whistle may be heard on its forward axis
with 90 per cent probability in conditions of still air on board a vessel
having average background noise level at the listening posts (taken to be 68
dB in the octave band centred on 250 Hz and 63 dB in the octave centred on 500
Hz).

In practice the range at which a whistle may be heard is extremely variable
and depends critically on weather conditions; the values given can be regarded
as typical but under conditions of strong wind or high ambient noise level at
the listening post the range may be much reduced.

(d) Directional properties

[*Formula*]

[*Formula*]

The sound pressure level of a directional whistle shall be not more than 4 dB
below the prescribed sound pressure level on the axis at any direction in the
horizontal plane within ±45 degrees of the axis. The sound pressure level at
any other direction in the horizontal plane shall be not more than 10 dB below
the prescribed sound pressure level on the axis, so that the range in any
direction will be at least half the range on the forward axis. The sound
pressure level shall be measured in that 1/3-octave band which determines the
audibility range.

(e) Positioning of whistles

When a directional whistle is to be used as the only whistle on a vessel, it
shall be installed with its maximum intensity directed straight ahead.

A whistle shall be placed as high as practicable on a vessel, in order to
reduce interception of the emitted sound by obstructions and also to minimize
hearing damage risk to personnel. The sound pressure level of the vessel's own
signal at listening posts shall not exceed 110 dB (A) and so far as
practicable should not exceed 100 dB (A).

(f) Fitting of more than one whistle

If whistles are fitted at a distance apart of more than 100 metres, it shall
be so arranged that they are not sounded simultaneously.

(g) Combined whistle systems

If due to the presence of obstructions the sound field of a single whistle or
of one of the whistles referred to in paragraph 1 (f) above is likely to have
a zone of greatly reduced signal level, it is recommended that a combined
whistle system be fitted so as to overcome this reduction. For the purposes of
the Rules a combined whistle system is to be regarded as a single whistle. The
whistles of a combined system shall be located at a distance apart of not more
than 100 metres and arranged to be sounded simultaneously. The frequency of
any one whistle shall differ from those of the others by at least 10 Hz.

_

2 Bell or gong

(a) Intensity of signal

A bell or gong, or other device having similar sound characteristics shall
produce a sound pressure level of not less than 110 dB at a distance of 1
metre from it.

(b) Construction

Bells and gongs shall be made of corrosion-resistant material and designed to
give a clear tone. The diameter of the mouth of the bell shall be not less
than 300 mm for vessels of 20 metres or more in length, and shall be not less
than 200 mm for vessels of 12 metres or more but of less than 20 metres in
length. Where practicable, a power-driven bell striker is recommended to
ensure constant force but manual operation shall be possible. The mass of the
striker shall be not less than 3 per cent of the mass of the bell.

_

3 Approval

The construction of sound signal appliances, their performance and their
installation on board the vessel shall be to the satisfaction of the
appropriate authority of the State whose flag the vessel is entitled to fly.

Annex IV Distress signals

1

The following signals, used or exhibited either together or separately,
indicate distress and need of assistance:

(a) a gun or other explosive signal fired at intervals of about a minute,

(b) a continuous sounding with any fog-signalling apparatus,

(c) rockets or shells, throwing red stars fired one at a time at short
intervals,

(d) a signal made by radiotelegraphy or by any other signalling method
consisting of the group . . . . . . (SOS) in the Morse Code,

(e) a signal sent by radiotelephony consisting of the spoken word `Mayday',

(f) the International Code Signal of distress indicated by NC,

(g) a signal consisting of a square flag having above or below it a ball or
anything resembling a ball,

(h) flames on the vessel (as from a burning tar barrel, oil barrel, etc),

(i) a rocket parachute flare or a hand flare showing a red light,

(j) a smoke signal giving off orange-coloured smoke,

(k) slowly and repeatedly raising and lowering arms outstretched to each side,

(l) the radiotelegraph alarm signal,

(m) the radiotelephone alarm signal,

(n) signal transmitted by emergency position-indicating radio beacons,

(o) approved signals transmitted by radiocommunication systems.

2

The use or exhibition of any of the foregoing signals except for the purpose
of indicating distress and need of assistance and the use of other signals
which may be confused with any of the above signals is prohibited.

3

Attention is drawn to the relevant sections of the International Code of
Signals, the Merchant Ship Search and Rescue Manual and the following signals:

(a) a piece of orange-coloured canvas with either a black square and circle or
other appropriate symbol (for identification from the air),

(b) a dye marker.