Canadian Hydrographic Service - Levels of Service

A relative risk classification for areas delineated by Canadian Hydrographic Service chart limits.

A classification is used to determine a Level of Service for charts and other CHS products and services.
The risk levels are defined as High, Medium and Low with the High-risk areas receiving more of our resources and more frequent updates.
Many factors are considered in the risk assessments such as the number of accidents in a given area, tanker routes, traffic, infrastructure, navigational complexity, and more.

For more information, please visit the Levels of Service section of the Canadian Hydrographic Services web site.

Coverage of raster CHS nautical charts in the Marine GeoGarage
705 available charts displayed on the total of 956 charts published 

>>> geolocalization with the Marine GeoGarage <<<

• High-risk charts (paper, ENC, raster) are reviewed at least once every five years and new editions are issued when necessary.
• BSB updates (file replacement) are issued monthly.
• Medium-risk charts are reviewed at least once every ten years and new editions are issued when necessary.
• Low-risk charts are generally updated through "Notices to Mariners" only.
• The release of new editions (ENCs and paper charts) is within three months of each other.
• Charts and Publications are always available.
• The four Catalogues of Nautical Charts and Publications are updated and published every two years.