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The International Maritime Organization (IMO) has decided to establish a new routeing system in Kattegat and the northern part of The Sound from 1 July 2020.

The intention is to reduce the large number of ships in the old Route T by establishing a new recommended route, Route S, along the Swedish coast from Læsø Island to The Sound. Along Route S, three traffic separation schemes is established in order to separate north- and southbound traffic. Vessels to and from The Sound shall use Route S and vessels to and from the Great Belt shall use Route T. The old Route T is changed slightly.

Where can I find more information?

Detailed information is published in Notice to Mariners.

An illustration showing the new routeing system is available in a pdf-file on this page.

New edition of charts

New editions of affected charts is now available from our retailers. The Swedish charts affected of the new routeing system is: 2, 8, 74, 92, 93, 922, 924, 925 och 931.

Is there anything special that I need to consider?

Since the current recommended routes will be used until 30 June, the current editions of some charts needs to be retained and used until the implementation of the new routeing system at 1 July.

Before the new routeing system came into force at 1 July the previous edition of charts 8, 92, 93 and 922 should be used. Since the new routeing system now is in use, only the latest edition of this charts should be used for navigation. If you are unsure which edition of the charts that is valid and which notice to mariners that affect the chart, you can find the information on the page Chart editions.

Electronic charts

Updated ENC’s (used by merchant shipping) is available.

Swedish Maritime Administration deliver continuously updated chart data to producers of plotters, apps and similar tools. Updates of your device is controlled of the manufacturer. For more information of when your device can be updated, please contact the manufacturer of your device.

When will small craft charts be available?

A new edition of small craft chart Västkusten Södra (Swedish west coast, southern part) and Sydkusten (south coast and the Sound) is planned for spring 2021. In the 2019 edition of Västkusten Södra, an information sheet is attached containing description and an illustration of the routeing system.

Who can answer my questions about my charts?

Questions are answered by customer service for charts sma@sjofartsverket.se or +46 10 478 58 10.

What are the consequences?

Along the Swedish coast

These changes will result in an increase in the number of merchant ships along the Swedish coast, east of Fladen and Lilla Middelgrund. The number of merchant ships in the area close to Kullen will therefore also increase.

Between Læsø Island and Tistlarna light

A precautionary area will be established northeast of Læsø Island where Route T and Route S will join. In this area, northbound vessels will approach from both Route T and Route S and proceed into the northern part of Route T. The southbound traffic will be split as some vessels proceed in Route T and others use Route S.

Which rules apply for traffic separation schemes (TSS)?

The International Regulations for Preventing Collisions at Sea (COLREG), most specifically Rule 10, apply to the water in and around a traffic separation scheme. In short, Rule 10 states:

  • A vessel shall proceed in the appropriate traffic lane in the general direction of traffic flow for that lane.
  • A vessel shall, so far as practicable, avoid crossing traffic lanes but if obliged to do so shall cross on a heading as nearly as practicable at right angles to the general direction of traffic flow.
  • A vessel navigating in areas near the terminations of traffic separation schemes shall do so with particular caution.
  • A vessel of less than 20 metres in length or a sailing vessel shall not impede the safe passage of a power-driven vessel following a traffic lane.


Inshore traffic zone: A designated area between a traffic lane and the coast. Inshore traffic zones may be used by vessels with a length less than 20 meters.

Notice to Mariners: The official publication for corrections of navigational charts.

Precautionary area: An area where a vessel must navigate with particular caution.

Recommended route: A suggested route for vessels in transit.

Routeing system: A system of routeing measures, for example recommended routes and traffic separation schemes, aimed at reducing the risk of casualties.

Traffic separation scheme: An area where opposing streams of traffic are separated into different traffic lanes.

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