The Canadian Aids to Navigation System 2011

Floating Aids to Navigation (Buoys)

The buoyage system used in Canada corresponds to the International Association of marine aids to navigation Lighthouse Authorities (IALA) Maritime Buoyage System which has been adopted by all major maritime nations in the world. This system includes lateral, isolated danger, cardinal and special buoys.

For lateral buoys, the IALA Maritime Buoyage System divides the world into two regions, “A” and “B”. Within Region “B”, which includes Canada, starboard hand buoys are red and port hand buoys are green. Within Region “A”, the application of these colours is reversed with red to port and green to starboard. Bifurcation buoys are similarly affected in that the predominant colour of starboard bifurcation buoys is red in Region “B” and green in Region “A” and that of port bifurcation buoys is green in Region “B” and red in Region “A”. All other aspects of the IALA Maritime Buoyage System are the same in both Regions “A” and “B”.

Since the shape and/or colour of a buoy and the colour and flash character of the light on the buoy indicate the function of the buoy, it is essential that mariners use up to date nautical charts with this system. Please see the Canadian Aids to Navigation System map for more details.

Lateral Buoys

Lateral buoys indicate the side on which they may be safely passed. There are five types of lateral buoys: port hand, starboard hand, port bifurcation, starboard bifurcation, and fairway.

Port Hand Buoy

  1. A port hand buoy marks the port (left) side of a channel or the location of a danger which must be kept on the vessel’s port (left) side when proceeding in the upstream direction.
  2. A port hand buoy is coloured green, displays identification letter(s) and odd number(s) and
    1. if it carries a light, the light is green and is a flashing (Fl)4s or quick flashing (Q)1s light,
    2. if it carries retroreflective material, such material is green,
    3. if it does not carry a light, it has a flat top, and
    4. if it carries a topmark, the topmark is a single green cylinder.

Starboard Hand Buoy

  1. A starboard hand buoy marks the starboard (right) side of a channel or the location of a danger which must be kept on the vessel’s starboard (right) side when proceeding in the upstream direction.
  2. A starboard hand buoy is coloured red, displays identification letter(s) and even number(s) and
    1. if it carries a light, the light is red and is a flashing (Fl)4s or quick flashing (Q)1s light,
    2. if it carries retroreflective material, such material is red,
    3. if it does not carry a light, it has a pointed (conical) top, and
    4. if it carries a topmark, the topmark is a single red cone pointing upward.

Port Bifurcation Buoy

  1. A port bifurcation buoy marks the point where a channel divides when viewed from a vessel proceeding in the upstream direction and indicates that the preferred or main channel is on the starboard (right) side of the buoy.
  2. A port bifurcation buoy is coloured green with one broad red horizontal band, displays identification letter(s), and
    1. if it carries a light, the light is green and is a composite group flashing Fl(2+1)6s or Fl(2+1)10s light,
    2. if it carries retroreflective material, such material is green,
    3. if it does not carry a light, the top of the buoy is flat, and
    4. if it carries a topmark, the topmark is a single green cylinder.

Starboard Bifurcation Buoy

  1. A starboard bifurcation buoy marks the point where a channel divides when viewed from a vessel proceeding in the upstream direction and indicates the preferred or main channel is on the port (left) side of the buoy.
  2. A starboard bifurcation buoy is coloured red with one broad green horizontal band, displays identification letter(s), and
    1. if it carries a light, the light is red and is a composite group flashing Fl(2+1)6s or Fl(2+1)10s light,
    2. if it carries retroreflective material, such material is red,
    3. if it does not carry a light, the top of the buoy is conical, and
    4. if it carries a topmark, the topmark is a single red cone pointing upward.

Fairway Buoy

  1. A fairway buoy indicates safe water. It is used to mark landfalls, channel entrances or the centre of a channel. It may be passed on either side but should be kept to the port (left) when proceeding in either direction.
  2. A fairway buoy is coloured red and white in wide vertical stripes of equal widths, displays identification letter(s), and
    1. if it carries a light, the light is white and is either a Morse “A” Mo(A)6s light or a long flash (LFl)10s light,
    2. if it carries retroreflective material, such material is white,
    3. if it does not carry a light, the top of the buoy is spherical, and
    4. if it carries a topmark, the topmark is a single red sphere.

Isolated Danger Buoys

  1. An isolated danger buoy is moored on, or above, an isolated danger which has navigable water all around it.
  2. An isolated danger buoy is black with one broad red horizontal band, displays identification letter(s), and
    1. if it carries a light, the light is white and is a group flashing Fl(2)5s or Fl(2)10s light,
    2. if it carries retroreflective material, such material is white,
    3. if it does not carry a light, it is normally spar shaped although other shapes may be used, and
    4. if it carries a topmark, the topmark is two black spheres, one above the other.

Cardinal Buoys

Cardinal buoys indicate the location of the safest or deepest water by reference to the cardinal points of the compass. There are four cardinal buoys: North, East, South and West.

If a cardinal buoy carries retroreflective material, such material is white. Where lights are not present, the cardinal buoy will normally be spar shaped although other shapes may be used.

North Cardinal Buoy

  1. A north cardinal buoy is located so that the safest water exists to the north of it.
  2. A north cardinal buoy is coloured black and yellow in approximately equal areas above the waterline, the top half of the buoy being black and the lower half being yellow. It displays identification letter(s) and
    1. if it carries a light, the light is white and is a quick flashing (Q)1s or very quick flashing (VQ)5s light, and
    2. if it carries a topmark, the topmark is two black cones, one above the other, pointing upward.

East Cardinal Buoy

  1. An east cardinal buoy is located so that the safest water exists to the east of it.
  2. An east cardinal buoy is coloured black with one broad yellow horizontal band. It displays identification letter(s) and
    1. if it carries a light, the light is white and is a group quick flashing three Q(3)10s or a group very quick flashing three VQ(3)5s light, and
    2. if it carries a topmark, the topmark is two black cones, one above the other, base to base.

South Cardinal Buoy

  1. A south cardinal buoy is located so that the safest water exists to the south of it.
  2. A south cardinal buoy is coloured black and yellow in approximately equal areas above the waterline, the top half of the buoy being yellow and the lower half being black. It displays identification letter(s) and
    1. if it carries a light, the light is white and is a group quick flashing six plus long flash (Q(6)+LFl)15s light or group very quick flashing six plus long flash(VQ(6)+LFl)10s light, and,
    2. if it carries a topmark, the topmark is two black cones, one above the other, pointing downward.

West Cardinal Buoy

  1. A west cardinal buoy is located so that the safest water exists to the west of it.
  2. A west cardinal buoy is coloured yellow with one broad black horizontal band. It displays identification letter(s) and
    1. if it carries a light, the light is white and is a group quick flashing nine Q(9)15s light or a group very quick flashing nine VQ(9)10s light, and
    2. if it carries a topmark, the topmark is two black cones, one above the other, point to point.

Special Buoys

Special buoys are used to convey specific information to the mariner. These buoys are not primarily used to assist in the navigation of the vessel. The shapes of special buoys have no significance and a variety of shapes may be used in practice.

Many special buoys are privately owned and, as such, must conform to the Private Buoy Regulations.

All special buoys, where lighted, will display yellow lights. With the exception of ODAS buoys, these lights will be flashing (Fl)4s, meaning that they will flash regularly at intervals of 4 seconds. Each ODAS Buoy, if lighted, will also carry yellow lights but will display a group flashing character of 5 flashes every 20 seconds, Fl(5)20s.

In cases where special buoys display retroreflective material, such material will be yellow. Additionally, where a buoy exhibits an orange symbol (e.g. Hazard), orange retroreflective material may be added to enhance the visibility of the symbol. Where no colour is required (i.e. white swimming and diving buoys) retroreflective material will be yellow.

Note:

Keep-out and Control buoys are governed by the Canada Shipping Act 2001, Vessel Operation Restriction Regulations. ODAS and Diving buoys are governed by the Canada Shipping Act 2001, Collision Regulations.

Anchorage Buoy

  1. An anchorage buoy marks the perimetre of a designated anchorage area.
  2. An anchorage buoy is coloured yellow, displays a black anchor symbol on at least two opposite sides, displays identification letter(s), and, if it carries a topmark, the topmark is a single yellow “X” shape.

Cautionary Buoy

  1. A cautionary buoy marks an area where mariners are to be warned of dangers such as firing ranges, racing courses, seaplane bases, underwater structures, aquaculture, of areas where no safe through channel exists, and of traffic separations. The mariner must consult his chart to determine the precise nature of the danger being marked.
  2. A cautionary buoy is coloured yellow, displays identification letter(s) and if it carries a topmark, the topmark is a single yellow “X” shape.

Control Buoy

  1. A control buoy marks an area where boating is restricted.
  2. A control buoy is coloured white and has an orange, open faced circle on two opposite sides and two orange horizontal bands, one above and one below the circles. A black figure or symbol inside the orange circles indicates the nature of the restriction in effect. It may display identification letter(s).

Diving Buoy

  1. A diving buoy marks an area where scuba or other such diving activity is in progress.
  2. A diving buoy is coloured white and carries a red flag not less than 50 centimetres square with a white diagonal stripe extending from the tip of the hoist to the bottom of the fly. It may display identification letter(s) and if it carries retroreflective material, such material is yellow.

Hazard Buoy

  1. A hazard buoy marks random hazards such as rocks, shoals or turbulent waters located outside the main channel.
  2. A hazard buoy is coloured white and has an orange diamond on two opposite sides and two orange horizontal bands, one above and one below the diamond symbols. Information words or symbols concerning the hazard may be placed within the diamond symbol, or if space doesn’t permit, between the orange bands. It may also display identification letter(s).

Information Buoy

  1. An information buoy displays, by means of words or symbols, information of interest to the mariner.
  2. An information buoy is coloured white and has an orange, open faced square symbol on two opposite sides and two orange horizontal bands, one above and one below the square symbols. The information words or symbols are black and are placed within the white face of the square symbol. It may display identification letter(s).

Keep-out Buoy

  1. A keep-out buoy marks an area where boats are prohibited.
  2. A keep-out buoy is coloured white and has an orange diamond containing an orange cross on two opposite sides and two orange horizontal bands, one above and one below the diamond symbols. It may display identification letter(s).

Mooring Buoy

  1. A mooring buoy is used for mooring or securing a vessel, seaplane, etc.
  2. A mooring buoy is coloured white and orange, the orange colour covering the top one third of the buoy above the waterline. It may display identification letter(s).

Ocean Data Acquisition System (ODAS) Buoy

  1. An ODAS buoy marks a scientific, meteorological or oceanographic station.
  2. An ODAS buoy shall not exhibit a shape that conflicts with any navigational mark.
  3. An ODAS buoy is coloured yellow, displays identification letter(s) and
    1. if it carries a light, the light is yellow and is a group flashing light of 5 flashes every 20 seconds, Fl(5)20s, and
    2. if it carries a topmark, the topmark is a single yellow “X” shape.

Swimming Buoy

  1. A swimming buoy marks the perimetre of a swimming area.
  2. A swimming buoy is coloured white, and may display identification letter(s)

Daytime Identification

During daytime, the colour and shape of a buoy indicates the buoy type, function and therefore interpretation by the mariner.

Buoy Colour

The following are the buoy colours used in the Canadian Buoyage System:

Buoy colours used in the Canadian Buoyage System
Buoy TypeColour
Port Green
Starboard Red
Fairway Red and White vertical stripes
Isolated Danger Black with one broad horizontal Red band
Port Bifurcation Green with one horizontal Red band
Starboard Bifurcation Red with one horizontal Green band
North Cardinal Black above Yellow
East Cardinal Black with one broad horizontal Yellow band
South Cardinal Yellow above Black
West Cardinal Yellow with one broad horizontal Black band
Anchorage Cautionary ODAS Yellow
Mooring Keepout Control Hazard Information White with Orange symbols
Swimming White
Diving White with Red and White flag

Buoy Shape

The shape of an unlighted buoy indicates the position of the buoy with respect to the channel and thus the side on which the buoy should be passed:

  1. A pointed (conical) shape indicates that the buoy is marking the starboard (right) side of the channel or the location of a danger which must be kept on the vessel’s starboard (right) side when proceeding upstream.
  2. A flat top or cylindrical (can) shape indicates that the buoy is marking the port (left) side of the channel or the location of a danger which must be kept on the vessel’s port (left) side when proceeding upstream. Flat topped (can) buoys are also used for some applications where the shape of the buoy has no significance (for example, special buoys and cardinal buoys). In the placement of such buoys, care is taken not to convey an unsafe message in the event that the meaning of the buoy is interpreted by shape only.
  3. A spherical shape indicates that the buoy is marking the centre of the channel or safe water and that it may be safely passed on either side although generally it should be kept on the vessel’s port (left) side when proceeding in either direction.

Topmarks

The use of topmarks as an additional means of daytime buoy identification is at present, restricted to lateral, cardinal, and isolated danger buoys in ice free conditions. Topmarks are not used in Canada to the extent that they are used in other parts of the world because of the environmental conditions which Canadian aids to navigation must endure. Mariners are cautioned not to rely solely on topmarks as a means of buoy identification as they are susceptible to damage and may be intentionally removed during winter and ice conditions.

Where installed, the Canadian Buoyage System includes topmarks for each buoy as follows:

Topmarks
Buoy TypeTopmark Description
Port and Port Bifurcation Single Green cylinder
Starboard and Starboard Bifurcation Single Red cone, pointing upward
Fairway Single Red sphere
Isolated Danger 2 Black spheres, one above the other
North Cardinal 2 Black cones, pointing upward
East Cardinal 2 Black cones, base to base
South Cardinal 2 Black cones, pointing downward
West Cardinal 2 Black cones, point to point

TIP:

A way of remembering the arrangement of the conical topmarks on Cardinal Buoys is to relate the direction of the points of the cones to the location of the black portion(s) of the buoy (e.g. on an East Cardinal, the upper cone pointing up and the lower cone pointing down relate to the black colour of the upper and lower portions of the buoy).

Nighttime Identification

At night, the colour and flash character of a buoy’s light indicate its function.

Buoy Light Flash Characters

Lights of different colours are used to assist recognition of the marks in the Canadian Aids to Navigation system. Red and Green lights for the lateral buoys, White lights for the cardinal, isolated danger and safe-water buoys and Yellow lights for special buoys

The buoy light characteristics for all buoys in the Canadian Aids to Navigation system shall conform to the “Specifications for Buoy Light Characteristics” detailed in table below. The primary character shall be used in all cases except for:

  1. when there is the need to distinguish between two identical buoys which are close to each other; or
  2. where emphasis is required (for example, the use of the secondary character “quick flash” to distinguish buoys marking a turn in a lateral buoy system); or
  3. when greater perception requirements demand or to improve the light’s availability in severe waves conditions.

The following are the names, abbreviations and descriptions of the flash characters of the lights used in the Canadian Buoyage System:

Port and Starboard
Primary: Flashing – (Fl)4s

A light (red for starboard and green for port) in which the total duration of light in a period is shorter than the total duration of darkness and is regularly repeated at a rate of 15 flashes per minute (1 flash every 4 seconds).

  • 0.5 sec. flash; 3.5 sec. eclipse
Secondary: Quick Flashing – (Q)1s

A light (red for starboard and green for port) in which identical flashes are repeated at the rate of 60 flashes per minute (1 flash every second).

  • 0.3 sec. flash; 0.7 sec. eclipse
Fairway
Primary: Morse Code A – Mo(A)6s

A white light in which a 0.3 second flash is followed by a 0.6 second eclipse then a 1 second long flash repeated at a rate of 10 times per minute (every 6 seconds).

  • 0.3 sec. flash; 0.6 sec. eclipse;
  • 1.0 sec. flash; 4.1 sec. eclipse;
Secondary: Long Flash – (LFl)10s

A white light in which a flash of 2 seconds duration is repeated at a rate of 6 flashes per minute (1 long flash every 10 seconds).

  • 2.0 sec. flash; 8.0 sec. eclipse;
Bifurcation
Primary: Composite Group Flashing Fl(2+1)6s

A light (red for starboard and green for port) in which a group of 2 flashes is followed by a single flash, the whole sequence being repeated 10 times per minute (every 6 seconds).

  • 0.3 sec. flash; 0.4 sec. eclipse;
  • 0.3 sec. flash; 1.2 sec. eclipse;
  • 0.3 sec. flash; 3.5 sec. eclipse;
Secondary: Composite Group Flashing – Fl(2+1)10s

A light (red for starboard and green for port) in which a group of 2 flashes is followed by a single flash, the whole sequence being repeated 6 times per minute (every 10 seconds).

  • 0.5 sec. flash; 0.7 sec. eclipse;
  • 0.5 sec. flash; 2.1 sec. eclipse;
  • 0.5 sec. flash; 5.7 sec. eclipse;
Isolated Danger
Primary: Group Flashing – Fl(2)5s

A white light in which a group of 2 flashes is regularly repeated 12 times per minute (every 5 seconds).

  • 0.4 sec. flash; 0.6 sec. eclipse;
  • 0.4 sec. flash; 3.6 sec. eclipse;
Secondary: Group Flashing – Fl(2)10s

A white light in which a group of 2 flashes is regularly repeated 6 times per minute (every 10 seconds).

  • 1.0 sec. flash; 1.0 sec. eclipse;
  • 1.0 sec. flash; 7.0 sec. eclipse;
North Cardinal
Primary: Quick Flashing – (Q)1s

A white light in which identical flashes are repeated at the rate of 60 flashes per minute (1 flash every second).

  • 0.3 sec. flash; 0.7 sec. eclipse
Secondary: Very Quick Flashing – (VQ).5s

A white light in which a flash is regularly repeated at a rate of 120 flashes per minute (1 flash every 0.5 second).

  • 0.2 sec. flash; 0.3 sec. eclipse;
East Cardinal
Primary: Group Quick Flashing   Q(3)10s

A white light in which a group of 3 flashes is regularly repeated 6 times per minute (every 10 seconds).

  • 0.3 sec. flash; 0.7 sec. eclipse;
  • 0.3 sec. flash; 0.7 sec. eclipse;
  • 0.3 sec. flash; 7.7 sec. eclipse;
Secondary: Group Very Quick Flashing – VQ(3)5s

A very quick flashing white light in which a group of 3 flashes is regularly repeated 12 times per minute (every 5 seconds).

  • 0.2 sec. flash; 0.3 sec. eclipse;
  • 0.2 sec. flash; 0.3 sec. eclipse;
  • 0.2 sec. flash; 3.8 sec. eclipse;
South Cardinal
Primary: Group quick Flashing + Long Flash – (Q(6)+LFl)15s

A white light in which a group of 6 quick flashes is followed by a single long flash, the whole sequence being regularly repeated 4 times per minute (every 15 seconds).

  • 0.3 sec. flash; 0.7 sec. eclipse;
  • 0.3 sec. flash; 0.7 sec. eclipse;
  • 0.3 sec. flash; 0.7 sec. eclipse;
  • 0.3 sec. flash; 0.7 sec. eclipse;
  • 0.3 sec. flash; 0.7 sec. eclipse;
  • 0.3 sec. flash; 0.7 sec. eclipse;
  • 2.0 sec. flash; 7.0 sec. eclipse;
Secondary: Group Very Quick Flashing + Long Flash – (VQ(6)+LFl)10s

A white light in which a group of 6 very quick flashes is followed by a single long flash, the whole sequence being regularly repeated 6 times per minute (every 10 seconds).

  • 0.2 sec. flash; 0.3 sec. eclipse;
  • 0.2 sec. flash; 0.3 sec. eclipse;
  • 0.2 sec. flash; 0.3 sec. eclipse;
  • 0.2 sec. flash; 0.3 sec. eclipse;
  • 0.2 sec. flash; 0.3 sec. eclipse;
  • 0.2 sec. flash; 0.3 sec. eclipse;
  • 2.0 sec. flash; 5.0 sec. eclipse;
West Cardinal
Primary: Group Quick Flashing – Q(9)15s

A quick flashing white light in which a group of 9 flashes is regularly repeated 4 times per minute (every 15 seconds).

  • 0.3 sec. flash; 0.7 sec. eclipse;
  • 0.3 sec. flash; 0.7 sec. eclipse;
  • 0.3 sec. flash; 0.7 sec. eclipse;
  • 0.3 sec. flash; 0.7 sec. eclipse;
  • 0.3 sec. flash; 0.7 sec. eclipse;
  • 0.3 sec. flash; 0.7 sec. eclipse;
  • 0.3 sec. flash; 0.7 sec. eclipse;
  • 0.3 sec. flash; 0.7 sec. eclipse;
  • 0.3 sec. flash; 6.7 sec. eclipse;
Secondary: Group Very quick Flashing – VQ(9)10s

A very quick flashing white light in which a group of 9 flashes is regularly repeated 6 times per minute (every 10 seconds).

  • 0.2 sec. flash; 0.3 sec. eclipse;
  • 0.2 sec. flash; 0.3 sec. eclipse;
  • 0.2 sec. flash; 0.3 sec. eclipse;
  • 0.2 sec. flash; 0.3 sec. eclipse;
  • 0.2 sec. flash; 0.3 sec. eclipse;
  • 0.2 sec. flash; 0.3 sec. eclipse;
  • 0.2 sec. flash; 0.3 sec. eclipse;
  • 0.2 sec. flash; 0.3 sec. eclipse;
  • 0.2 sec. flash; 5.8 sec. eclipse;
Special (except ODAS)
Primary: Flashing – (Fl)4s

A yellow light in which the total duration of light in a period is shorter than the total duration of darkness and is regularly repeated at a rate of 15 flashes per minute (1 flash every 4 seconds)..

  • 0.5 sec. flash; 3.5 sec. eclipse;
Secondary - ODAS (Ocean Data Acquisition System)
Primary: Group Flashing – Fl(5)20s

A yellow light in which a group of 5 flashes is regularly repeated 3 times per minute (every 20 seconds).

  • 0.5 sec. flash; 1.5 sec. eclipse;
  • 0.5 sec. flash; 1.5 sec. eclipse;
  • 0.5 sec. flash; 1.5 sec. eclipse;
  • 0.5 sec. flash; 1.5 sec. eclipse;
  • 0.5 sec. flash; 11.5 sec. eclipse;

TIP:

As a way of remembering the light flash characters of the East, South and West Cardinal buoys, the number of flashes in each group for these lights is the same as the figure on the clock face in the corresponding compass direction (e.g. the 3 flashes in each group for the East cardinal corresponds to three o’clock). The long flash in the South Cardinal character ensures that there is no confusion between the 6 flashes per group of this buoy and the 9 flashes per group of the West Cardinal.

Buoy Light Colour

The following are the colours of the buoy lights used in the Canadian Buoyage System:

Colours of the buoy lights used in the Canadian Buoyage System
BUOY TYPELIGHT COLOUR
Port and Port Bifurcation Green
Starboard and Starboard Bifurcation Red
Fairway, Isolated Danger, and all Cardinals White
All Special buoys Yellow

Retroreflective Material

Retroreflective material is applied to unlighted buoys to aid in their night time identification with a flashlight or other light source and to lighted buoys as a back up to the light. For all buoys other than special buoys the colour of the retroreflective material is the same as that of the light which would be appropriate for each buoy. In cases where a special buoy is equipped with retroreflective material for use with number or letter plates/backgrounds, the colour of that material will be yellow. Additionally, where a buoy exhibits an orange symbol (e.g. Hazard), orange retroreflective material may be added to enhance visibility of the symbol.

Note:

Swimming and diving buoys, which are white in colour, will use yellow retroreflective material.

Other Characteristics

Buoy Numbering

Only starboard and port hand buoys are numbered; starboard hand buoys with even numbers and port hand buoys with odd numbers. Buoy numbers increase in the upstream direction and are kept in approximate sequence on both sides of the channel by omitting numbers where required. Buoy numbers are usually preceded by one or two letters to facilitate channel identification. All other types of buoys are identified by letters only. All types of buoys may be identified by a name in addition to a number or letter identification. Private buoys are not numbered or lettered as they are not government-owned. Instead, they display the letters “PRIV” and other information required by the Private Buoy Regulations.

Sound Signals

Any of the buoy types in the Canadian Buoyage System may be fitted with a bell or a whistle that is activated by the motion of the buoy in the water. The use of such buoys is generally restricted to coastal waters where there is sufficient buoy motion to activate the sound device and where there is a requirement for an audio signal to enable location of the buoy under low visibility conditions.

Radar Reflectors

Many buoys are fitted with radar reflectors to improve their visibility on the radar screen.

Radar Beacons (RACONS)

When precise identification of a buoy is considered essential, the buoy may be fitted with a radar beacon (RACON). Section 2 of Radio Aids to Navigation provides a complete list of RACONS with information such as name and location, range, arc and identifier. The List of Lights, Buoys and Fog Signals publication will also provide some information on the RACON.

Marking of New Dangers

New dangers such as a shipwreck or the discovery of an uncharted shoal or rock can occur suddenly and unexpectedly in waters which mariners have come to regard as safe. The Canadian Buoyage System makes the following special provisions for these hazards:

  1. Primary choice for marking a new danger is the Isolated Danger Aid moored on or installed above the danger. Lateral buoys, cardinal aids or cautionary buoys can also be used.
  2. One or more of the aids marking the new danger may be duplicated, the duplicate being identical to its partner in all respects.
  3. In general, any lighted lateral or cardinal aid used to mark a new danger will display the most rapid flash character available for that aid.
  4. A new danger may be marked by a RACON coded Morse “D”.
  5. Special measures taken to mark a new danger may be discontinued when information concerning the new danger has been sufficiently promulgated.