Areas are identified by risk – high, medium and low – with the charts for the high-risk areas receiving more frequent updates.
You can find out about the risk designations in your region by viewing our list of charts or interactive maps.
About Risk Area Classifications
In order to determine a relative risk classification for areas delineated by CHS chart limits and to use this classification to subsequently determine a Level of Service for charts and other CHS products and services. The risk levels were defined as High, Medium and Low.
A model was developed and used as a tool to provide an indication of high, medium and low risk areas delineated by CHS chart limits. The model used accident occurrences (number vessels grounded, tonnage, persons involved) and the chart 'wellness' (off-datum, number NTMs, last edition date, unincorporated data, etc.) as some of the parameters for determining risk. Additional known criteria (tanker routes, traffic, infrastructure, pilotage, navigational complexity, etc) with an appropriate risk weighting was used to determine the final contribution for the determination of the national risk area classification.
Each chart or product in the CHS portfolio based on these risk area classifications was then classified as a High risk, Medium risk or a Low risk product. The results of this CHS national risk classification will be used to determine the resource allocation to produce and maintain CHS products in the given risk areas. The allocation of CHS resources to support charts and products is directly related to their risk assessment i.e. those products within a high-risk area will receive the largest resource allocation and will be maintained on a pre-defined maintenance cycle. The remaining products in the medium or low risk areas will be maintained but on a longer maintenance cycle and a different level of service than the products in the high-risk areas.
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