The Baltic Sea is an enclosed sea, covering an area of 386, 000 square kilometers in northern Europe. It is bordered by Sweden and Denmark on the west, Finland, Estonia, Latvia, Lithuania and Russia on the east, and Poland and Germany on the south.
The Baltic Sea is the most important channel to transport the cargoes of these countries. Nowadays the chief cargoes shipped across the sea are timber from Russia, Finland and Sweden, iron form Sweden, coal from Poland, and fish. The transportation in the Baltic Sea has never been easy. Many of its harbors are too shallow for the larger ships. The water of the Baltic is not very salty because many fresh rivers flow into it, so it freezes more easily. Many of its ports are blocked by ice in winter.