CHS Chart 2043: Lower Niagara River and Approaches

Scale identification for CHS Charts

We refer to the relationship between the size of the chart and the earth as 'natural scale.' For example, 1:15 000 means that 1 unit on the chart equals 15 000 units on the earth. The following are examples of different types and scales of charts and their uses.

• Harbour charts are:
  • large scale, 1:2 001 to 1:20 000
  • used for navigation in harbours or intricate, hazardous, shoal-infested waters
• Approach charts are:
  • 1:20 001 to 1:50 000
  • used for approaching coasts where a lot of detail is required
• Coastal charts are:
  • 1:50 001 to 1:150 000
  • used in fisheries charts
  • used to show continuous extensive coverage with sufficient inshore detail to make landfall sightings easy
• General charts:
  • are 1:150 001 to 1:500 000
  • used in fisheries charts
  • give extensive offshore coverage with sufficient inshore detail to make landfall sightings easy
• Sailing charts are:
  • 1:500 001 and smaller
  • used for offshore navigation beyond sight of land