At the heart of the regime for the Area established by Part XI of the United Nations Convention on the Law of the Sea and the 1994 Agreement relating to the Implementation of Part XI of the United Nations Convention on the Law of the Sea is the so-called parallel system, elaborated in article 153 of the Convention. One essential element of the parallel system is a system of site-banking, whereby, in the case of polymetallic nodules, reserved areas are set aside for the conduct of activities by the Authority through the Enterprise either by itself or in association with developing States.
The system of site-banking is elaborated in annex III, article 8, of the Convention, in the Agreement (annex, section 3, para. 11 (b), and in the Regulations on Prospecting and Exploration for Polymetallic Nodules in the Area (regulations 15 to 17). Each application for exploration for polymetallic nodules must cover a total area, which need not be a single continuous area, sufficiently large and of sufficient estimated commercial value to accommodate two mining operations and to be divided into two parts of “equal estimated commercial value”. One part is to be allocated to the applicant and the other is to become the reserved area. The application area must not exceed a total of 150,000 square kilometres. The applicant is required to indicate the coordinates dividing the area under application into those two parts. Designation of the reserved area may either precede the application for approval of a plan of work for exploration or, may be simultaneous with such an application. The application must contain sufficient data and information to enable the Council to designate a reserved area based on the estimated commercial value of each part. The Council, on the basis of the data and information submitted by the applicant, if found satisfactory, and taking into account the recommendation of the Legal and Technical Commission, designates the part of the area under application which is to be a reserved area. The areas designated become reserved areas as soon as the plan of work for the non-reserved area is approved and the contract is signed.
In 2005, the Council, on the recommendation of the Legal and Technical Commission, designated sectors W2 and E2 of the area under application (18,462 square kilometres and 54,284 square kilometres respectively, the total being 72,746 square kilometres) as the reserved area (ISBA/11/C/10, Decision of the Council relating to a request for approval of a plan of work for exploration by the Federal Republic of Germany represented by the German Federal Institute for Geosciences and Natural Resources, Selected Decisions 11, 42). The first seven reserved areas were contributed by the registered pioneer investors at the time of the Preparatory Commission for the International Seabed Area and for the International Tribunal for the Law of the Sea.