The Kattegat (Danish Kattegat [ˈkadəgad], Swedish Kattegatt) is a 20,000 km² to 35,000 km² large and on average about 80 meters deep, sea area between Jutland (Denmark) and the Swedish west coast. Near Skagen it borders on the Skagerrak.
The International Hydrographic Organization defines the northern boundary of "Kattegat, Belte and Sound" as follows:
North. A line passing Skagen (North Cape of Denmark) and Paternosterskären (57°54'N, 11°27'E) and further northeastward through the archipelago to the island of Tjörn.
However, it does not separate the Kattegat from Belten and Sund. The Store Danske defines this border as follows:
In the southwest, the line between the tip of the Ebeltoft Peninsula and Gniben on Sjællands Odde separates the sea area from Samsø Bælt, and in the southeast, the line between Gilbjerg Hoved and Kullen divides Kattegat from Öresund.
Art. 4 lit. b of Regulation (EU) 2020/123, on the other hand, establishes the northern boundary of the (fishing) area of the same name by a line from the Skagen lighthouse to the Tistlarna lighthouse and from there to the nearest point on the Swedish coast.
The Kattegat is seen as either an arm of the Baltic Sea, an arm of the North Sea, or, in traditional Scandinavian terms, neither.
The connection to the open North Sea is via the Skagerrak and, since the February flood of 1825, via the Limfjord. However, the latter connection is navigable only by small ships.
Ocean-going vessels reach the Kattegat by circumnavigating the northern tip of Jutland, Skagen. The Baltic Sea is connected to the Kattegat by the Öresund, the Great Belt and the Little Belt (together called the sea area "Belte and Sund").
The name Kattegat is derived from the Dutch words kat "cat" and gat "hole" or "passage". In the seafaring days of the Hanseatic League and later, the Kattegat was feared for its many shoals and narrow navigable waters. This is how captains came to say that the Kattegat was as narrow as a cat's hole. Numerous wrecks testify to the former difficulties of navigation in the Kattegat.
An earlier name of the water was Jutland Sea (Old Norse Jótlandshaf).
Today, the eastern Kattegat in particular is a busy sea area, with a significant amount of traffic passing through it to and from Gothenburg, Copenhagen, and the Baltic ports. Several important ferry lines cross or pass through the Kattegat, such as the Frederikshavn-Gothenburg, Kiel-Oslo, Kiel-Gothenburg lines.
Along the Swedish Kattegat coast runs the Kattegattleden, a tourist bicycle path between Helsingborg in the south and Gothenburg in the north.
Offshore wind energy is produced in the Kattegat. For example, the Anholt offshore wind farm has 111 Siemens SWT-3.6-120 wind turbines with a total rated output of 400 MW. It was thus the most powerful offshore wind farm in Denmark when it was officially commissioned on September 4, 2013.