Download maritime limits and boundaries

Availability of lines and zones

The lines and zones for the Dutch claims in the North Sea are available on this page. All data are expressed in the geodetic datum WGS84, which can be assumed to be equal to ETRS89 and NAD83 here. Your application may require a datum transformation. See for more information the horizontal coordinate systems page.

All limits at a constant distance from the baseline have been calculated using a calculation precision of 10 m and a point resolution of 25 m. Each zip file contains three data formats:
ESRI SHAPE for ArcGIS (extensions DBF, PRJ, SHP and SHX, incl. metadata in XML-format) KML for Google Earth (extension KML)
a simple ASCII-format (extension DAT)
This latter format has coordinates as degrees, arc minutes and arc seconds for first geographical latitude and second longitude. The full set of metadata is registered at the Dutch National Geo registry, where it is also available to download the metadata in XML format.

The lines and zones are calculated several times a year. Not every relevant new nautical chart immediately results in new boundaries on this site. The only correct way to determine with certainty if a position lies inside or outside a zone is to plot it on the most recent large-scale chart and to subsequently determine the shortest distance to the baseline. Be aware that this shortest distance could also be a distance to a straight baseline.

Announcement of changes

The Netherlands Hydrographic Service informs stakeholders about changes in the maritime zones via a Notice to Mariners and via a mailing list. Leave your email address on the contact page to become a member of this mailing list, using ‘registration mailing list maritime limits’ as the subject.

Terms of use

The source must be mentioned explicitly, when using and distributing the data. This could either be done in the data itself or in a separate colophon. It is recommended that you use one of the following 2 text examples: - This data has been reproduced with the approval of the Hydrographic Service of the Royal Netherlands Navy. - Source: Hydrographic Service, Royal Netherlands Navy.
It is prohibited to employ commercial activities with the data provided, except for those activities for which explicit agreement has been reached with the Hydrographic Service. This includes the prohibition against generating any substantial income - directly or indirectly - using the provided data. It also includes the prohibition against distributing the data without payment, in case commercial interests of others are compromised.
The Hydrographic Service reserves its right to exercise its moral rights (Art. 6 bis of the Berne Convention) on reproduced material, in which the provided data has been used.
The provided data should not be distributed to third parties without the prior written approval of the Hydrographic Service.
After the use of the data has ended, it must be destroyed.

Thinning

The curved nature of the normal baselines and the limits make a high point resolution necessary. For some applications, an approximation of these lines with fewer points is necessary. Hereto, the computer program TSP page is available.

Changes 2012

16 February (see Dutch NtM 90/12): paper chart 1458 (December 2011) and ENC NL401456 (February 2012). The maximum changes are: +1300m (1M line); +1150m (3M line); +1150m (6M line); +1100m (12M line); +1100m (24M line).

16 February (see Dutch NtM 90/12): ENC NL400110 (November 2011). The maximum changes are: -1250m (1M line); +550m (3M line); +500m (6M line); -200m (12M line); -200m (24M line).

29 March (see Dutch NtM 162/12): block correction Zandmotor for chart 122. The maximum changes are: +1100m (1, 3, 6 and 12M line); +100m (24M line).

Changes in zones due to changes in low tide elevations on paper charts 1456 and 1458.

4 October (see Dutch NtM 454/12): two block corrections for paper chart 1458.
New low-tide elevations on paper charts 1456 (see Dutch NtM 246/12) and 1458 (see Dutch NtM 379/12) were also taken into account.

December 13th, 2012 (see Dutch NtM 565/12): block correction for paper chart 1458. The maximum changes are -1200m (1M line); -100m (3M line); +15m (6M line); +10m (12M line); -10m (24M line).

Changes 2011

Changes in zones due to ENC NL401546.

11 August (see Dutch NtM 333/11): ENC NL401456 (August 2011) and paper chart 1546 and changes in low tide elevations of paper chart 1458. The maximum changes North of Ameland and Schiermonnikoog are: +3000m (1M line); +2200m (3M line); +1850m (6M line); +1700m (12M line); +1500m (24M line). The maximum changes West of Den Helder and Texel are: -1500m for the 1, 3, 6, 12 and 24M line.

28 april (see Dutch NtM 289/11): paper chart 1456 (October 2010), 1458 (October 2010) and 1460 (May 2011). The maximum changes are: -2500m (1M line); -2100m (3M line); -1800m (6M line); -1800m (12M line); -1600m (24M line).