"On the long-term average, the Baltic Sea is ice-covered for about 45% of its surface area at the maximum annually. The ice-covered area during such a typical w

"On the long-term average, the Baltic Sea is ice-covered for about 45% of its surface area at the maximum annually. The ice-covered area during such a typical winter includes the Gulf of Bothnia, the Gulf of Finland, Gulf of Riga, Väinameri in the Estonian archipelago, the Stockholm archipelago and the Archipelago Sea." http://en.wikipedia.org/wiki/Baltic_Sea http://en.wikipedia.org/wiki/Baltic_Sea