Article 5
In the case of the sea adjacent to a bay, the baseline from which the breadth of the territorial sea is measured shall—
if the bay has only one mouth and the distance between the low-water lines of the natural entrance points of the bay does not exceed 24 nautical miles, be a straight line joining the said low-water lines;
if, because of the presence of islands, the bay has more than one mouth and the distances between the low-water lines of the natural entrance points of each mouth added together do not exceed 24 nautical miles, be a series of straight lines across each of the mouths drawn so as to join the said low-water lines;
if neither paragraph (a) nor (b) of this article applies, be a straight line 24 nautical miles in length drawn from low-water line to low-water line within the bay in such manner as to enclose the maximum area of water that is possible with a line of that length.