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Miscellaneous Notices to Mariners

5.2 Official Norwegian Electronic Navigational Charts (ENC) for Norwegian Waters

Official electronic navigational charts (ENC) are vector charts produced in compliance with the specifications given by the International Hydrographic Organization, and are approved by a national hydrographic office.

The sources for Norwegian ENCs are either digitalized or scanned analog charts, or a database. The data is compiled into a seamless database in which each ENC is a cell. Each cell is identified by a unique number.

The content of charts and ENCs in the same area is not always identical. The ENC often contains more detailed data.

Depths along the quay

Quay depth is not a object class in the ENC. They are regular soundings showing its true position. Quay depths are taken either on the quay or two meters away from the quay depending on when the measurements were taken. Quay depths maybe presented slightly away from the quay in the electronic navigational chart (ENC) in order to improve readability in ECDIS.

Update Files (ER Updates)

An advantage with ENCs is the possibility for automatic updates. Update files (ER) are issued every fortnight. Within a 14 day period, all notices from the last Notice to Mariners (Efs) will be included. The ERs may also include updates that have not been issued in the Efs.

Temporary (T) and preliminary (P) notices are distributed for the ENCs in the same way as other updates. All ER updates are distributed through PRIMAR. For larger updates New Editions of an ENC will be issued. A New Edition may also be issued for technical reasons.

Terms Used

New dataset: ENC dataset that has not been issued for navigational purposes earlier.

Update: Amendments to existing dataset.

New edition: It also includes new data that have not been released earlier, in addition to all the previous updates.


Use of modern equipment makes it possible to extend the use of nautical chart information beyond what it is intended for. We strongly advise against this.

It is at all times the mariners own responsibility to familiarize themselves with and use the information in a chart in a responsible manner. Do take into consideration the constraints of the information the charts provides.

Report Feedback on Norwegian ENCs

Report errors, omissions or suggest improvements on the Norwegian Electronical Navigational Charts (ENC) in the web-based feedback system ENC Improver.

ENC Improver has been designed to provide users with a simple system to give feedback on Norwegian ENCs. Everybody who has an ENC license for navigation will receive user access to ENC Improver through their supplier.

Add a point on the chart in ENC Improver and describe the problem. A monitoring system is in place to follow up received feedback. To submit feedback, Internet access is required.

In addition to ENC Improver, errors, omissions or suggestions for improvements on the Norwegian ENCs can also be sent to

User Bands

Norwegian ENCs are divided into the following user bands:

User bands
Navigational purposeNameScale RangeUsed in Norwegian ENCsMatching Scale Range
1 Overview <1:1 499 999 1 500 000 200 NM, 96 NM
2 General 1:350 000 – 1:1 499 999 700 000, 350 000 48 NM, 24 NM
3 Coastal 1:90 000 – 1:349 999 180 000, 90 000 12 NM, 6 NM
4 Approach 1:22 000 – 1:89 999 22 000 3 NM, 1.5 NM
5 Harbour 1:4000 – 1:21 999 12 000, 8000 0.75 NM, 0.5 NM, 0.25 NM
6 Berthing > 1:4000 3999 and larger < 0.25 NM
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