As per the provisions of UN Convention on the Law of the Sea (UNCLOS), the Coastal States can establish from the baseline:

(i) The Territorial Sea of 12 nautical miles;

(ii) The Exclusive Economic Zone (EEZ) of 200 nautical miles; and

(iii) The Outer Limits of the Continental Shelf beyond 200 nautical miles.

While the territorial sea and EEZ follow essentially from the promulgation of the baseline, the outer limits of the Continental Shelf have to be established by physical survey which involves the determination of the water depth and foot of slope through bathymetry and sedimentary rock thickness through seismic reflection and refraction. Claims in relation to the outer limits of the Continental Shelf have to be submitted to the Commission on the Limits of Continental Shelf (CLCS) within 10 years of entry into force of the Convention for that State. The Convention came into force on 16.11.94 and India ratified the same in June 1995. India thus must submit all the necessary data to the CLCS by June 2005.

Indications are that after delineation is undertaken, India would be in a position to make exclusive claim on the continental shelf with an area of more than 1 million sq. km of continental shelf beyond the EEZ. In case India does not submit claim before the CLCS, the continental shelf beyond 200 nautical miles would lie in international waters and India would have the same claim to it as other members of the International Seabed Authority (ISBA). It is, thus, imperative that India establishes claim over the continental shelf.

The class of work envisaged in establishing the claim is new to India. Commission on the Limits of Continental Shelf had brought out Scientific and Technical Guidelines for Delineation of Outer Limits of Continental Shelf. Since then, various steps have been taken for laying the claim. The baseline data have been collected by National Hydrographic Office and baselines are being finalised. The NHO has been entrusted with acquisition, processing and certification of the bathymetry data for estimating the foot of the slope and 2500 m. isobath in accordance with the format specified in the guidelines of the Commission. The bathymetric data were collected by Geological Survey of India (GSI) and National Hydrographic Office (NHO) in Bay of Bengal and Arabian Sea. The data of GSI and NHO have been compared. The gap areas were identified and survey was undertaken in the gap areas. The data of NHO and GSI were consolidated and are presently being processed at National Hydrographic Office. The preparations for seismic survey towards estimating the thickness of sedimentary rocks have been initiated. Directorate General of Hydrocarbons has been identified as the agency for certification of seismic data. The available seismic data is being compiled. National Centre for Antarctic and Ocean Research (NCAOR), Goa has been assigned the responsibility of implementation of this multi-institutional programme. Various organisations viz. Oil and Natural Gas Commission (ONGC), National Institute of Oceanography (NIO), National Geophysical Research Institute (NGRI) are also closely associated with this programme.