Ice gets thicker in the Bay of Bothnia.
In the northern Bay of Bothnia there is 45-65 cm thick fast ice in the archipelago. Farther out 30-50 cm thick, consolidated and in places ridged drift ice, approximately to the line Malören - Oulu 1. The icefield is in places is difficult to force. Farther out there is a lead, which runs off Skellefteå to Malören and further via Oulu 1 to Ulkokalla. There is new ice and 5-15 cm thick level ice in the lead. Further south 20-50 cm thick very close ice mixed with thick floes of consolidated brash ice and new ice.
In the southern Bay of Bothnia there is 20-40 cm thick fast ice in the archipelago. Farther out first there is a lead with new ice. Then there is 5-15 cm thick level ice and very close ice. Off Kokkola there is brash ice barrier, difficult to force.
In the Quark in the inner archipelago there is 20-40 cm thick fast ice. Farther out 5-20 cm thick drift ice mixed with new ice and older heavier floes.
In the Sea of Bothnia in the archipelago there is 10-40 cm thick fast ice. Farther out there is a zone of thin drift ice off the fast ice.
In the Archipelago Sea in the inner archipelago, there is 10-30 cm thick fast ice and thin level ice.
In the western Gulf of Finland there is 10-25 cm thick fast ice and thin level ice in the archipelago.
In the eastern Gulf of Finland there is 15-35 cm thick fast ice in the inner archipelago. Farther out new ice and thin close ice approximately to the line Harmaja - Tiiskeri - Suursaari. In the Gulf of Vyborg and off St. Petersburg there is 10-30 cm thick close and very close ice to the longitude of Haapasaari.
Icebreakers: Polaris, Sisu and Frej assist in the northern Bay of Bothnia. Otso and Thetis assist in the southern Bay of Bothnia. Voima assists in the eastern Gulf of Finland.
Restrictions to navigation: Minimum ice class and deadweight required of assisted vessels:
Tornio, Kemi and Oulu, IA of more than 4000 tons.
Raahe and Kalajoki, IA of more than 2000 tons.
Kokkola, Pietarsaari and Vaasa, IA and IB of more than 2000 tons.
Kaskinen, I and II of more than 2000 tons.
Loviisa, Kotka and Hamina, IA and IB of more than 2000 tons and IC and II of more than 3000 tons.
The traffic separation scheme in the Quark is temporarily out of use due to ice conditions from 18th February.
Vessels bound for Gulf of Bothnia ports in which traffic restrictions apply shall, when passing the latitude 60°00'N, report their nationality, name, port of destination, ETA and speed to ICE INFO on VHF channel 78. This report can also be given directly by phone +46 31 699 100.
The ice chart of the whole Baltic Sea (pdf) is published in the autumn twice a week (Monday and Thursday) and daily when the amount of ice increases until until ice break-up in spring. It represents current ice situation, ice breaker positions and traffic restrictions in the Baltic Sea.
The simplified charts are updated once a week at the latest on Tuesday morning. The first one represents measured level ice thicknesses, ice coverage and sea surface temperature. The reference charts represent average, 1965 – 1986, ice situation on that day (= normaali), last week´s situation, last year´s situation and the positions of the ice breakers.
Explanation of chart's finnish words