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Chart Correction (Notices to Mariners)

Conditions of fairways, coastal waters and harbors are constantly changing. For the safety of navigation, it is indispensable for mariners to recognize such conditions and to correct nautical charts in possession to make them up-to-date.

1. Notices to Mariners

Notices to Mariners are composed of "Notices for small corrections to charts (including block charts)" for correcting charted data and information and "Temporary information" announced in Navigational Warnings and others.  A printed booklet of Notices to Mariners is published by the Japan Coast Guard as of every Friday.  Users can download them from the homepage of the Japan Hydrographic and Oceanographic Department.
Since printing of Temporary information was ceased as of October 2008, the Japan Hydrographic Association is now providing the copy service of such information to users.

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2. Electronic Notices to Mariners (ER)

Similarly to nautical charts, electronic navigational charts (ENCs) should also be updated.  The updating information (ER) can be downloaded from the homepage of the Japan Hydrographic Association.  If any customer so desires, the Association provides the customer with Electronic Notices to Mariners on a CD-ROM.  For details, click here.

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3. Corrections to Nautical Charts

In order to keep the contents of nautical charts to the updated conditions, corrections to charts by Notices to Mariners are performed with hand.  For such complicated corrections to considerable changes occurred on coastlines, soundings, etc., a correction block attached to the last part of a Notices to Mariners booklet should be pasted on the affected portion of a chart concerned.
In this connection, the Japan Hydrographic Association is providing customers with "Tracings for chart correction" to simplify user's hand correction.

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