For all practical purposes, the breadth of the Contiguous zone may not exceed 24 nautical miles, measured from the baselines . It consists of an area beyond the territorial sea in which the coastal State may act to prevent any violation of its customs, fiscal, immigration or sanitary laws and regulations.
The concept of the Contiguous zone has a customary foundation; according to some authors, its origins can be traced back to the 18th century. It enjoyed its hour of glory on the occasion of the Conference of The Hague in 1930 and was put into explicit form in the Geneva Conventions of 1958 and 1960.
It should be pointed out that, except for the powers attributed to the coastal State regarding customs, fiscal, immigration or sanitary matters, the legal regime appplying to the Contiguous zone is that of the high sea unless an Exclusive Economic Zone (EEZ) has been established in the area (in which case, the applicable legal regime will be that of the EEZ).
1. In a zone contiguous to its territorial sea, described as the contiguous zone, the coastal State may exercise the control necessary to:
a) prevent infringement of its customs, fiscal, immigration or sanitary laws and regulations within its territory or territorial sea;
b) punish infringement of the above laws and regulations committed within its territory or territorial sea.
2. The contiguous zone may not extend beyond 24 nautical miles from the baselines from which the breadth of the territorial sea is measured.