Detailed information on chart corrections

All corrections will be described in text, specifying the action (addition, deletion, replacement) and position.

For corrections involving changes to buoyage, descriptions will be provided in text, similar to those found in Notices to Mariners (EfS). References to the publication ‘Chart 1 INT 1 (Symbols, abbreviations and terms used in nautical charts)’ may be included as a guide for users.

The chart corrections are provided in English.

If a correction cannot be adequately described using text, an update to the relevant chart will be made and a new edition will be published.

Generalisation: Corrections described for the largest scale
Users making corrections to their paper charts should pay particular attention to the generalisation of chart corrections.

Chart corrections are based on the largest-scale charts. Typically, users will begin by applying corrections to the largest-scale charts. For smaller-scale charts, users must determine how to apply the corrections themselves, i.e. they must generalise the information accordingly.

The same principle applies when adding objects. Users must ensure that all listed positions in the chart correction are included on the chart. However, at smaller scales, it may only be necessary to include objects at selected positions.

Example:
For corrections such as adding an aquaculture site (area) that extends beyond the boundary of the largest-scale chart, users must first apply the correction to the smaller-scale chart, in order to identify the relevant boundary positions for updating the largest-scale chart.

Example:
For corrections such as adding multiple marked measuring stations, some of which are located outside the boundary of the largest-scale chart, users must determine which measuring stations should be included on the largest-scale chart and which belong on charts at other scales.