How does the North Sea connect to the Baltic Sea?

The North Sea and the Baltic Sea are connected through two primary routes: natural straits and an artificial waterway.

Natural Connections

The primary natural connection is through the Kattegat, a strait located between the Jutland peninsula of Denmark and southwestern Sweden. The connection functions as follows:12
* Northward: The Kattegat connects to the North Sea via the Skagerrak, a deep inlet that separates southern Norway from northern Jutland.12
* Southward: The Kattegat links to the Baltic Sea through three narrow channels: The Sound (Øresund), the Great Belt, and the Little Belt.13

Artificial Connection

The Kiel Canal in northern Germany provides a vital, man-made shipping route between the two seas. Extending 98 km (61 miles) from Brunsbüttelkoog on the North Sea to Holtenau on the Baltic, it serves as the shortest and most convenient passage for maritime traffic, eliminating the need for vessels to navigate around the Jutland peninsula.4