Geography of the North Sea
The geography of the North Sea studies coastal and submarine features as well as the people who live on its coasts. It is bounded by the east coasts of England and Scotland to the west and the northern and central European mainland to the east and south, including Norway, Denmark, Germany, the Netherlands, Belgium, and France. In the south-west, beyond the Straits of Dover, the North Sea becomes the English Channel. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively. In the north, it opens in a widening funnel shape to the Norwegian Sea, which lies in the very north-eastern part of the Atlantic.
The International Hydrographic Organization defines the limits of the North Sea as follows:
On the Southwest. A line joining the Walde Lighthouse (France, 1°55'E) and Leathercoat Point (England, 51°10'N).
On the Northwest. From Dunnet Head (3°22'W) in Scotland to Tor Ness (58°47'N) in the Island of Hoy, thence through this island to the Kame of Hoy (58°55'N) on to Breck Ness on Mainland (58°58'N) through this island to Costa Head (3°14'W) and to Inga Ness (59'17'N) in Westray through Westray, to Bow Head, across to Mull Head (North point of Papa Westray) and on to Seal Skerry (North point of North Ronaldsay) and thence to Horse Island (South point of the Shetland Islands).
...
Wikipedia