The maritime boundary between Denmark and Norway is 259 nautical miles in length and divides the waters of the North Sea and the Skagerrak. Running from east to southwest, the boundary begins at a tripoint with Sweden and ends at a tripoint with the United Kingdom in the North Sea. The initial 1965 maritime agreement defined the boundary with eight turning points. It was subsequently modified by an exchange of notes in 1968, and again 1973, to update one turning point, and better define the connecting segments as arcs of great circles, or geodesics, rather than “straight lines.”