The Canadian Aids to Navigation System 2011
Aids to Navigation are devices or systems, external to a vessel, which are provided to assist mariners in determining position and course, to warn of dangers or obstructions or to advise of the location of the best or preferred route.
The Canadian Coast Guard is mandated, though not obligated, to provide aids to navigation in Canadian waters with the exception of waterways such as the Trent Severn and Rideau waterways, which are served by Parks Canada. The Canadian Coast Guard should provide, as deemed practical and necessary, such aids to navigation as justified by existing policies and directives.
To facilitate the proper understanding and interpretation of their function, aids to navigation are to be used in conjunction with other marine publications. In particular, nautical charts, Lists of Lights, Buoys and Fog Signals, Radio Aids to Marine Navigation, Sailing Directions, the Canadian Aids to Navigation System, GPS/DGPS publications and the Owner’s Guide to Private Buoys. Information concerning nautical charts and Sailing Directions may be obtained from the Canadian Hydrographic Service, Department of Fisheries and Oceans, Ottawa at the Canadian Hydrographic Service.
The Canadian Aids to Navigation System
The Canadian Aids to Navigation System is comprised of a mix of visual, aural and electronic aids to navigation.
Visual aids are short range aids to navigation including buoys, daybeacons, daymarks and lights. In Canada, a combined Lateral-Cardinal system of visual aids is used. Knowledge of the characteristics of each of these basic types of aids is a prerequisite to the safe use of the system.
The lateral system of buoyage in use in Canadian waters is IALA System B (see IALA Maritime Buoyage System on page 22 of this manual). Lateral aids may be in the form of either buoys or fixed aids. These aids indicate the location of hazards and the safest or deepest water by indicating the side on which they are to be passed.
The correct interpretation of lateral aids requires knowledge of the direction of buoyage known as the “upstream direction”. The upstream direction is the direction taken by a vessel when proceeding from seaward, toward the headwaters of a river, into a harbour or with the flood tide.
When a vessel is proceeding in the upstream direction, starboard hand aids must be kept to starboard (right) and port hand aids must be kept to port (left).
Cardinal aids may be in the form of either buoys or fixed aids. However, their predominant use is in the form of buoys in the Canadian system.
Cardinal aids indicate the location of hazards and the safest or deepest water by reference to the cardinal points of the compass. There are four cardinal marks, North, East, South and West which are positioned so that the safest or deepest water is to be found to the named side of the mark (e.g. to the north of a north cardinal mark).
Aural aids are sound producing devices which serve to warn the mariner of a danger under low visibility conditions. Such aids include buoy mounted bells and whistles which are activated by wave action and fog signals on shore. Most aural aids are operated when visibility is reduced to less than two nautical miles.
The electronic aids used in the Canadian system include radar reflectors, radar beacons, and Differential Global Positioning System. The advent of e-Navigation and its many possibilities is being monitored for potential impacts and opportunities, such as the introduction of virtual aids to navigation, along with the Automatic Identification System, to better meet the changing needs of our clients.
Radar reflectors are passive devices which are used to strengthen the radar image of aids to navigation whereas radar beacons are active devices which, by means of a coded radar image, provide precise identification of the location they are marking.
Differential Global Positioning System is a method of improving the accuracy of the position derived from Global Positioning System receivers by correcting the inherent inaccuracies of the Global Positioning System signal and comparing it to a known geographic position.
A detailed listing of all lighted visual aids and all fog signals is contained in the publication List of Lights, Buoys and Fog Signals.
A detailed listing of all electronic aids is contained in the publication Radio Aids to Marine Navigation.
Winter ice conditions may necessitate the removal of buoys and the closing of the navigation season. The operation of aids to navigation on shore may also be discontinued during such times. Some lights may be replaced by lights of lower intensity.
In less severe ice conditions the unlighted summer buoys may be left in place or lighted buoys may be replaced by unlighted winter buoys. Mariners who use channels marked by such buoys before the official opening of the navigation season are cautioned that these aids may not be in their advertised positions due to storms and shifting ice.
The opening and closing of navigation, the seasonal removal, substitution or position of buoys and the temporary discontinuance of other aids to navigation are always advertised. Mariners are encouraged to check local marine radio broadcasts, Notices to Shipping, and published Notices to Mariners for this information.
Most buoys and many fixed aids are equipped with retroreflective material. This retroreflective material is coloured to signify the type of the aid and, for buoys at close range, displays the identification numbers, letters or symbols.
The Canadian Coast Guard recommends that vessels making use of aids to navigation be equipped with searchlights to enable them to identify this reflective material when necessary. It is recommended that large vessels be equipped with boat-mounted searchlights with at least 75,000 candelas and that small vessels carry a hand-held searchlight with at least a 3 watt bulb and 6 volt battery with a nominal power of 4,000 candelas.
Speed and Navigation
Canadian aids to navigation systems cannot be expected to perform up to expectations in situations involving excessive speed. The Canadian Coast Guard advises mariners to conform to local speed restrictions where applicable and to exercise good judgement in all situations.
Mariners are especially urged to reduce speed and proceed with caution under conditions of poor weather or visibility (i.e. night navigation, in hazard or high traffic areas and where ice has formed). Under these conditions, consideration must be given to the possibility of equipment failures, to limitations of the aids to navigation, and to reduced reaction times; problems which are only compounded by high speeds.
Rule 6 of Collision Regulations, under the Canada Shipping Act 2001, sets out guidelines relating to safe speed.
Cautions in the use of Aids to Navigation
- Mariners are cautioned not to rely solely on buoys for navigation purposes. Navigation should be by bearings or angles from fixed aids on shore or other charted landmarks and by sounding or through the use of satellite or radio-navigation systems, whenever possible.
- Most aids to navigation are not under continuous observation and mariners should be aware that failures and displacements do occur. The Canadian Coast Guard does not guarantee that all aids to navigation will operate as advertised and in the positions advertised at all times. Mariners observing aids to navigation out of operation, out of position, damaged or missing are responsible for reporting such problems to the nearest Canadian Coast Guard Marine Communication and Traffic Services Centre on VHF Ch. 16 immediately or to the closest Canadian Coast Guard office.
- Aids to navigation are subject to damage, failure and dislocation. This may be caused by ice, storms, vessel strikes and power failures. Ice and storm damage may be widespread and require considerable time to repair. Isolated damage may exist for a long time without being discovered and reported. Floating aids and pier lights in or near the water which are exposed to particularly rigorous strain during ice movement are at the greatest risk of damage.
- Mariners are cautioned that aids to navigation may fail to exhibit their advertised characteristics. Lights may be extinguished or aural signals may not function due to ice, collisions, mechanical failure and, in the case of bell and whistle buoys, calm water. The shape of an aid to navigation may be altered by ice formation or damage. The colour of an aid to navigation may be altered by freezing spray, marine growth or fouling by birds.
- Buoy positions shown on nautical charts should be considered as approximate positions. There are a number of limiting factors in accurately positioning buoys and their anchors. These factors include prevailing atmospheric and sea conditions, tidal and current conditions, seabed conditions and the fact that buoys are moored to anchors by varying lengths of chain and may drift about their charted positions within the scope of their moorings.
- Since moving ice is liable to move buoys from their advertised positions, mariners should proceed with extreme caution under these circumstances.
- Mariners are reminded that because of differences in horizontal datum (i.e. NAD 27, NAD 83), grids on charts of an area may vary from one chart to another. When plotting the positions of aids to navigation by the latitude and longitude method, the results should be checked against other available information.
- In some instances it is necessary to establish a buoy in close proximity to or on a navigational hazard (e.g. shoal, reef or ledge, etc.). In these instances the buoy symbol may be off set slightly on the chart in the direction of the preferred navigable water so that the existing hazard depicted on the chart will not be overprinted by the buoy symbol. Such off sets will be indicated on the chart by means of an arrow.
- Mariners are cautioned not to navigate too closely to a buoy and risk collision with it, its mooring or with the underwater obstruction which it marks.
- Many lights are equipped with sun switches. These lights, both on shore and on most buoys, are unlit between sunrise and sunset. Mariners unable to see these lights during the daylight hours should not assume that the equipment is malfunctioning.
- Many light stations which exhibit a main light 24 hours per day are equipped with an emergency light which is brought into service automatically in the event of failure. These emergency lights are white, have a standard character of group flashing (6)15s and operate throughout the hours of darkness. Emergency lights are normally visible at 5 nautical miles on a dark night with a clear atmosphere. The List of Lights, Buoys and Fog Signals publications identify which aids to navigation are equipped with emergency lights.
- Atmospheric conditions can have a considerable effect on light transmission and the visibility of lights. For example:
- The distance to a light cannot be reliably estimated from its apparent brightness.
- It is difficult to distinguish between a white light and a yellow or blue light seen alone at night, except at a short distance.
- Under some atmospheric conditions white and yellow lights take on a reddish hue.
- Alternating lights with phases of different luminous intensity may change their apparent characteristics at different distances because some phases may not be visible.
- When observed from similar distances, lower intensity lights are more easily obscured by conditions of low visibility than more powerful lights. Coloured lights are often of lower intensity than white lights and are more quickly lost under unfavourable circumstances.
- Ice, frost or moisture may form on the windows of lantern during cold weather and more particularly this may reduce their visibility and could cause coloured lights to appear white.
- A light exhibiting a very short flash may not be visible at as great a range as a light exhibiting a longer flash.
- The mariner should not rely solely on colour when using a sector light, but should verify the vessel’s line of position by taking a bearing on the light. On either side of the line of demarcation, between white and red, and also between white and green, there is always a small arc of uncertain colour.
- When the arc of visibility of a light is cut off by sloping land, the bearing at which it disappears or appears will vary with the observer’s distance and height of eye.
- The sighting of a light may be adversely affected by a strongly illuminated background.
- In view of the varying distances at which a fog signal can be heard at sea, and the frequent occurrence of fog near, but not observable from, a fog signal, mariners are cautioned that:
- When approaching land in fog, they should not rely implicitly upon these fog signals, but should always take soundings, which in nearly all cases will give sufficient warning of danger.
- Distance from a fog signal should not be judged by the power of the sound. Under certain atmospheric conditions the sound may be lost at a very short distance from the signal. These conditions may vary within a very short period of time. Mariners should not assume that a fog signal is not in operation because they do not hear it, even when in close proximity.
- Visual aids to navigation provided by the Canadian Coast Guard are for the purpose of assisting marine navigation. Hunters, snowmobilers and ice fishers are cautioned that aids to navigation installed for marine navigation purposes cannot be relied upon after the close of the marine navigation season. Such aids may stop operating without warning and will not be re-commissioned by the Canadian Coast Guard until the next opening of marine navigation season.
The Canadian Coast Guard continuously strives to improve efficiencies in the provision of the Canadian aids to navigation system. In some instances, these efficiencies are achieved through the use and implementation of new products and technologies. These include but are not limited to changes in the use of plastic buoys rather than steel; and the use of LED lanterns. Mariners are advised that every effort has been made by the Canadian Coast Guard to ensure that new equipment provides safe and reliable aids to navigation systems. If there are any concerns please contact the Superintendent, Aids to Navigation in your region.
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