North Sea between and among rivers, artificial harbours, and the sea. The Kiel Canal, connecting the North Sea with the Baltic Sea, is the most heavily used artificial seaway in the world reporting an average of 89 ships per day not including sporting boats and other small watercraft in 2009. It saves an average of , instead of the voyage around the Jutland peninsula. The North Sea Canal connects Amsterdam with the North Sea. North Sea The North Sea is a marginal sea of the Atlantic Ocean located between the United Kingdom (particularly England and Scotland), Denmark, Norway, Sweden, Germany, the Netherlands,
Geology of the Baltic Sea on the Baltic water body became the Yoldia Sea. About 10,700 years ago the continued land rise separed the Baltic water body from the ocean again and Yoldia Sea turned into the Ancylus Lake. This lake lasted until 10,000 years before present when a new connection to the ocean was established, this time in the Danish straits forming the Littorina Sea. Land rise did not close off Littorina sea but it made its connection the ocean over time more shallow allowing less salt water to enter it, thus gradually it evolved into the current Baltic Sea with somewhat brackish water.