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Marine traffic

The North Sea is important for marine transport and its shipping lanes are among the busiest in the world. Major ports are located along its coasts: Rotterdam, the busiest port in Europe and the fourth busiest port in the world by tonnage as of 2013, Antwerp (was 16th) and Hamburg (was 27th), Bremen / Bremerhaven and Felixstowe, both in the top 30 busiest container seaports, as well as the Port of Bruges-Zeebrugge, Europe's leading ro-ro port.

Fishing boats, service boats for offshore industries, sport and pleasure craft, and merchant ships to and from North Sea ports and Baltic ports must share routes on the North Sea. The Dover Strait alone sees more than 400 commercial vessels a day. Because of this volume, navigation in the North Sea can be difficult in high traffic zones, so ports have established elaborate vessel traffic services to monitor and direct ships into and out of port.

The North Sea coasts are home to numerous canals and canal systems to facilitate traffic 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 250 nautical miles (460 km; 290 mi), instead of the voyage around the Jutland peninsula. The North Sea Canal connects Amsterdam with the North Sea.