Distress
signals
Distress signals must be used only to indicate need of
assistance. Misuse of them may put the lives of others at risk and is illegal.
The following signals may be used to indicate distress.
1. Rockets or shells
that throw red stars, fired into the air one at a time at short intervals.
2. A signal:
·
made
by radiotelegraphy or by any other signalling method consisting of the letters
S O S in Morse Code (••• - - - •••)
·
sent
by marine radio consisting of the spoken word: mayday.
3. A square flag
having above or below it a ball or anything resembling a ball.
4. A rocket parachute
flare or a hand-held flare showing a red light.
5. A smoke signal
giving off orange-coloured smoke.
6. Slowly and
repeatedly raising and lowering arms outstretched to each side.
7. A rectangle of
international orange-coloured material with either a:
·
black
letter V
·
black
square and circle, or
·
dye
marker.
Short Blast - about one second duration
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Prolonged Blast - four to six seconds duration
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I am altering my course to starboard.
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One short blast on a horn or similar device.
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I am altering my course to port.
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Two short blasts on a horn or similar device.
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I am operating astern propulsion (Engines in reverse -
vessel slowing down, stopping or intends going astern).
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Three short blasts on a horn or similar device.
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Signal by vessel in doubt as to the intentions of the
other vessel.
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Five
short blasts on a horn or similar device.
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Vessel nearing a blind bend in a channel or river.
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One long blast on a horn or similar device.
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8. The International
signal of distress indicated by N.C.
9. Continuous
sounding of any fog-signalling apparatus.
10. Signal transmitted by an Emergency Position Indicating Radio
Beacon (EPIRB).
Manoeuvring
and warning signs
Large vessels sound a series of specific signals
to indicate their intentions to other vessels in the vicinity. Some of the more
common signals are listed below.
Diver
below flag
The
signal flag for the letter A shown below is used internationally to indicate: I
have a diver below - keep well clear at slow speed.
The flag is coloured white and blue and may be displayed either from a vessel
or floating buoy. It is an offence in South Australia to exceed four knots
within 50 metres of a vessel or buoy displaying this flag.
Navigation lights
Vessels underway at night must show navigation lights.
Navigation lights indicate the:
- presence of a vessel
- approximate direction of travel
- type of the vessel ie - power-driven or sailing.
Small
rowing and sailing boats
Small rowing and sailing boats are the only vessels that don’t need
navigation lights when operating at night, but operators of these vessels must
instead carry a torch or lantern showing a white light and show it in
sufficient time to prevent a collision.
Under
12 metres in length
Vessels under 12 metres in length use the following
lights in various combinations, depending on whether the vessel is sail or
power-driven, underway or at anchor.
Light
|
Masthead
light
|
Sidelights
|
Stern
light
|
All-round
light
|
Colour
|
white
|
red/green
|
white
|
white
|
Angle of
visibility
|
225°
|
112.5°
|
135°
|
360°
|
Range of
visibility
(nautical miles)
|
2
|
1
|
2
|
2
|
As with channel and other lateral markers, the green sidelight indicates
starboard and red indicates port, when looking in the direction of travel.
Power-driven
vessels while underway
Power-driven
vessels while underway must show either:
- a masthead light, separate or combined sidelights
and a sternlight or
- a white light visible all round and separate or
combined sidelights, provided that the all-round white light is positioned
so as not to interfere with the operator's vision.
The masthead or all-round white light must be a minimum of one metre above the
sidelights.
Sailing
vessels while underway
Sailing vessels while underway must show:
- separate or combined sidelights and a sternlight
or
- a single, tri-colour lantern, fixed to the
masthead.
Vessels
at anchor: sail or power-driven
Vessels at anchor, either sail or power-driven, must
show a single white light visible all round.
Dredge
signals
Vessels undertaking dredging, diving or underwater
operations display either two black diamonds in daylight hours or two green
lights at night to indicate the side on which it is safe for other vessels to
pass. This is the only time when red and green lights may not indicate a
vessel’s direction of travel.
A dredge also displays either two black balls in daylight hours or two red
lights at night on the side where dredging is taking place – to
indicate where it's unsafe to pass.
Giving way
If you are required to give way to another vessel,
take early and positive action so that your intentions are clear. Avoid making
a series of small changes in speed or course that may not be apparent to the
other vessel.
If another vessel is required to give way to you, maintain your present speed
and course unless it is obvious that a collision may occur. In this case stop,
slow down or turn away.
Rivers
and channels
All vessels – including sail vessels – must always be
navigated on the right (starboard) side of a river or channel in the direction
of travel.
Power-driven
vessels crossing
If a vessel approaches on your right (starboard) side
you must stop, slow down or change course so as to keep out of its way.
If a vessel approaches on your left (port) side, it
should give way to you. Maintain your present speed and course unless it
appears that a collision may occur.
Sailing
and power-driven vessels crossing
Powered vessels normally give way to sail. However, in
harbours and channels where there is restricted room, small sailing vessels
must give way to large powered vessels that cannot easily manoeuvre. Similarly,
sailing vessels must also give way to other vessels that are restricted in
their ability to manoeuvre, including fishing vessels that may have nets or
other equipment over the side.
Power-driven
vessels meeting head-on
Each vessel must alter course to the right (starboard)
so as to pass on the port side of the other.
Vessels
overtaking
An overtaking vessel (including a sailing vessel) may
pass on either side if safe, but must keep well clear of the vessel being
overtaken.
Lateral marks
Lateral Marks are usually positioned to define
well-established channels and indicate port and starboard sides of the navigation
route into a port.
Port mark is coloured red and the basic shape is a can.
Starboard mark is coloured green and the basic shape is conical.
By night a port buoy shows a red light and a starboard buoy shows a green
light.
Cardinal marks
A cardinal mark indicates where the safest water may be found and
is best used together with a compass. It shows where the mariner can safe pass
safely and may:
- indicate the deepest water in an area
- show the safest side to pass a danger
- draw attention to a feature in a channel such as a
bend, junction or an end of a shoal.
Think of a
clock face when remembering the lights on cardinal marks. Three flashes
for east, six flashes for south and nine flashes for west.
By day the colour scheme can be remembered by noting that the
black segment is positioned where the cones point.
- North – the top mark points up and black segment is at
the top
- East – the top marks point outward and there are black
segments top and bottom
- South – the top mark points downward and the black
segment is at the bottom
- West – the top marks point inward and the black segment
is in the middle.
Top marks
Black double cones, clearly separated.
Colours - black and yellow horizontal bands with the position of the black band
or bands relative to the respective cardinal points.
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North
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Top mark points up,
black band above yellow band.
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East
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Top mark points
outward, black bands above and below yellow band
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South
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Top mark points down,
black band below yellow band.
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West
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Top mark points
inward, black band between yellow bands.
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Channel
markers
Channel markers indicate the port and starboard limits of a narrow
channel that has been dredged in a river or the approaches to a harbour to
allow safe passage of large vessels.
The waters outside the channel may be shallow or conceal rocks and other
hazards to navigation. Navigating outside the marked channel could result in a
vessel running aground and sustaining serious damage.
Entrances to harbours or breakwaters may utilise different distinguishing
characteristics, for example, white flashing lights. Please seek advice from
the local marine authority.
Types of markers
Two types of marker are used to indicate the port and starboard
limits and these may be either fixed or floating: see picture.
The positioning of the two types of marker is determined by the
general direction taken by a vessel when entering a harbour or proceeding
upstream.
Under this convention a vessel entering, for example, the Port Adelaide River
would keep the port (red) markers on her port side and the starboard (green)
markers on her starboard side.
When leaving the harbour or proceeding downstream the situation is reversed,
meaning that the port markers should now be passed on the vessel’s starboard
side and vice-versa.
Isolated
danger marks
Isolated danger marks are placed on, or moored above,
an isolated danger of minimal area below the water around the mark. The water
around the mark is safe to navigate. The colours are red and black horizontal
stripes and the mark is, when practicable, also fitted with a black top mark of
two vertically aligned spheres.
Isolated danger marks are not always positioned centrally over a danger so to
be safe do not pass too close to the mark.
If the mark is lit, the light will be white showing a
group of two flashes. Two white flashes of light = two spheres.
Safe watermarks
Safe water marks show that there is navigable water
all around the mark and can be used as a centre line, mid-channel or landfall
buoy.
The shape of the buoy is spherical, pillar or spar (a
round pole shape) and is coloured with red and white vertical strips. The top
mark that's fitted when practicable to pillar and spar buoys, is spherical and
red.
If lit, it shows an isophase occulting or single long flashing white light. An
isophase is a special class of light which alternates eclipses and flashes of
exactly equal duration. The buoy shape is optional but should not be in
conflict with the buoy used for a lateral or special mark.
Operators of vessels are cautioned that large
commercial vessels may pass close by these marks.
Port
closed or channel blocked signal
The port closed or channel blocked signal is used to indicate
a thoroughfare to navigation that's blocked. The signal may come from
a shore station or from any vessel that's blocking the channel.
The marks are made up of three black shapes in a vertical line.
The highest and lowest of these shapes shall be a ball and the middle on a cone
with apex upwards.
Three all round lights in a line where they can be best seen. The highest and
lowest of these lights shall be red and middle light shall be green.
Channel blocked signals are increasingly likely to be seen in the River Murray
and lakes as the ongoing effects of low water levels cause restrictions to
some areas of water.
Day marks
Day marks are shown by day in all weathers on boats to
denote certain situations that may limit the vessel’s ability to respond to
other vessels, including when visibility is restricted, and must be recognised
by vessel operators.
Vessel
is restricted in its ability to manoeuvre
Black ball, black
diamond and black ball.
For example boats engaged in cable laying, replenishment at sea, underwater
operation, servicing navigation marks or towing, where towing affects the
manoeuvrability.
When at anchor, vessel also shows anchor shape. This signal does not indicate
distress or a need for help.
Vessel
at anchor
One black ball.
Located forward, where best seen.
Not required for boats of less than seven metres. Used when at anchor not
in a channel or channel approach, or a usual anchorage.
Vessel
under power with sails set
One black cone, point down.
Located forward, where best seen.
Power-driven
vessel towing another vessel
One black diamond on
each vessel where best seen if length of tow exceeds 200 metres.
Vessel
aground
Three black balls.
Located where best seen, but not required for boats of less than 12 metres.
This signal does not indicate distress or a need for help.
Vessel
not under command
Two black balls.
Located where best seen. Not required for boats of less than 12 metres.
Indicates an inability to manoeuvre, but does not signal distress or a need for
help.
Boats
fishing
Two black cones.
Indicates trawls, nets or other gear - underway or at anchor, point
inwards. If fishing vessel is less than 20 metres, she may instead show a
basket.
Vessel
constrained by her draught
One cylinder.
Located where best seen indicates a power-driven vessel restricted to a narrow
channel by her draught and therefore unable to deviate from course.