Kattegat, a body of water between Denmark and Sweden. The strait forms the central link in the chain of waters connecting the Baltic and the North Sea. There are many shoals and frequent storms, making the Kattegat dangerous for ships. The strait is about 137 miles (220 km) long and from 35 to 100 miles (56 to 160 km) wide. The ports of Göteborg (Sweden) and Aarhus (Denmark) lie near the Kattegat.