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THE QUEBEC REGION BULLETIN
AUGUST - SEPTEMBER 2011/VOLUME 14/NUMBER 4
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Aids to navigation
Addressing needs as they evolve
Aids to navigation systems DFO  M. Carrier

Have you ever wondered why the Canadian Coast Guard (CCG) installs buoys and lighted structures to help navigators?

It’s important to point out that CCG aids to navigation technicians use a methodology cited as a reference by the International Association of Marine Aids to Navigation and Lighthouse Authority (IALA). Using this reference, they can design and revise aids to navigation systems in keeping with a grid that analyzes the hazards specific to a given site and to the type of vessels navigating there.

The aid systems make navigation safe but should never replace normal and careful navigation practices. The design of the devices takes into consideration that every navigator has on board updated marine charts, a compass, direction finder and nautical publications.

Aids to navigation can:

  • Signal the approaches to harbours;
  • Signal channels and recommended routes;
  • Lead to government wharfs and fishing harbours;
  • Identify hazards lying near these waterways;
  • Guide navigators in well mapped areas; and
  • Permit the provisioning of isolated communities.

However, the Department is not required to provide aids in the following situations:

  • Places for which there are no adequate charts;
  • Cases that benefit single users;
  • Places covered by agreements with other authorities; and
  • Places where an aid’s targeted degree of reliability cannot be maintained.

Aid systems are reviewed on average every five years, taking into consideration the following elements:

  • Accident frequency;
  • Changes in traffic or activities;
  • Changes in the hazard;
  • Technological changes; and
  • Maintenance or replacement for reliability reasons.

In addition to on-going consultation with users, the aid system review is done in four phases.

The first phase involves analyzing a given site. For each site, the technician gathers data on weather (winds, waves, visibility) and bathymetry as well as on tide and current conditions. He validates these data by consulting users. The technician also compiles statistics on the characteristics of vessels and the routes they follow, traffic volume and shoreline particularities. Each aid system is designed to be perceivable at least 75 percent of the time during the worst month of the shipping season. 

The second phase consists of drawing up a preliminary list of the hazards—for instance the distance from a hazard or from another passing ship, the minimum width of the channel or the turning angle—and then attribute a degree of significance to those hazards.

During the need analysis, the third phase, the technician assesses the cumulative effect of the hazards to measure the existing system’s capacity to mitigate them, and seeks to improve the effectiveness of the system.

The final phase, the operational analysis, determines the combination and types of aids required (visual range in nautical miles, colour, daytime or night-time use, its function as a marker to signal turning, lateral movement or the presence of a hazard on the waterway, etc.). The cost of the proposed measures are also analyzed during this phase.

Once the analysis is completed, recommendations are submitted to navigators in the study area. Their comments are taken into consideration and examined in order to find the best solution.


Daniel Lefebvre
Canadian Coast Guard
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