03 What does the Baltic Sea Ice Code of 1980 describe?

The code describes the ice conditions in port areas, fairways, coastal sections, and marked sea lanes. It is intended, together with the ice charts and the textual ice reports, to inform the ship’s command of the ice and navigation conditions to be encountered. The various sea and fairway districts of each country are designated by letters: AA, BB, CC, and so on. Each district is divided into sections, which have identification numbers from 1 to a maximum of 9.

Key for reporting ice and shipping conditions Baltic Sea Ice Code of 1980 (AB SB TB KB)

  • First number: AB Quantity and arrangement of sea ice
  • Second number: SB State of development of the ice
  • Third number: TB Topography or shape of the ice
  • Fourth number: KB Navigation conditions in the ice

First number: AB Quantity and arrangement of sea ice

0Ice free
1Open water Coverage less than 1/10
2Very loose ice Coverage 1/10 to 3/10
3Loose ice Coverage 4/10 to 6/10
4Dense ice Coverage 7/10 to 8/10
5Very dense ice Coverage 9/10 to 9+/10
6Ice pushed together or coherent ice Coverage 10/10
7Ice outside the edge of the fast ice
8Solid ice
9Gully in very dense or collapsed ice or along the edge of the fast ice
/Unable to report

Second number: SB State of development of the ice

0New ice or dark nilas less than 5 cm thick
1Heller Nilas oder Eishaut 5 bis 10 cm dick
2Gray ice 10-15 cm thick
3Grey white ice 15 to 30 cm thick
4White ice, 1st stage 30 to 50 cm thick
5White ice, 2nd stage 50 to 70 cm thick
6Medium thick first year ice 70 to 120 cm thick
7Ice predominantly thinner than 15 cm with slightly thicker ice
8Ice predominantly 15 to 30 cm thick with slightly thicker ice
9Ice predominantly thicker than 30 cm, with slightly thinner ice
/Unable to report

Third number: TB Topography or shape of the ice

0Ice predominantly thicker than 30 cm, with slightly thinner ice
1Small ice floes – 20 – 100 m across
2Medium ice floes – 100 – 500 m across
3Big ice floes – 500 – 2000 m across
4Vast or giant ice floes or level ice – more than 2000 m across
5Rafted ice
6Compacted slush or shuga, or compacted brash ice
7Hummocked or ridged ice
8Thaw holes or many puddles on the ice
9Rotten ice
/Unable to report

Fourth number: KB Navigation conditions in the ice

0Navigation unobstructed
1Navigation difficult or dangerous for wooden vessels without ice sheathing
2avigation difficult for unstrengthened or low-powered vessels built on iron or steel. Navigation for wooden vessels even with ice sheathing not advisable
3Navigation without icebreaker assistance possible only for high-powered vessels
of strong construction and suitable for navigation in ice
4Navigation proceeds in lead or broken ice-channel without the assistance of an icebreaker
5Icebreaker assistance can only be given to vessels suitable for navigation in ice and of special size
6Icebreaker assistance can only be given to vessels of special ice class and of special size
7Icebreaker assistance can only be given to vessels after special permission
8Navigation temporarily closed
9Navigation has ceased
/Unknown