There are two definitions for “bank,” depending on its use in UNCLOS:
(a)The word “banks” in UNCLOS Article 9, when referring to river banks, means those portions of land that confine a river.
(b)The word “bank” in UNCLOS Article 76(6) means a submarine elevation located on the seabed of a continental margin over which the depth of water is relatively shallow; this includes the seabed of an island’s continental shelf as permitted by Article 121, over which the depth of water is relatively shallow.
In LOAC-governed situations under the “other rules of international law” clauses in UNCLOS, a different definition may apply. The same may be the situation if the UN Charter supersedes UNCLOS or if jus cogens norms apply.
Consolidated Glossary ¶ 10 has two definitions related for “bank.” The first relates to the continental shelf: “[a] submarine elevation located on a continental margin over which the depth of water is relatively shallow.” Former Glossary ¶ 10 phrased this definition differently: “an elevation of the sea floor located on a continental (or an island) shelf, over which the depth of water is relatively shallow.”
The second relates to the term as used in connection with a river: “that portion of land that confines a river.” Former Glossary ¶ 10 phrased this definition differently: “a shallow area of shifting sand, gravel, mud, etc., as a sand bank, mud bank, etc., usually constituting a danger to navigation and occurring in relatively shallow waters.” Because of the term’s use as related to river banks and banks beneath the ocean’s surface, a two-part definition is necessary.
UNCLOS Article 9 says that if a river flows directly into the sea, the baseline shall be a straight line across its mouth between points on the low water line of its banks. Territorial Sea Convention Article 13 applies the same rule for the low tide line. UNCLOS Article 76(6), as part of the continental shelf definition, says that notwithstanding its Article 76(5) submarine ridge provisions, the shelf ’s outer limit shall not exceed 350 nautical miles from baselines from which the territorial sea’s breadth is measured. The Article 76(6) proviso does not apply to submarine elevations that are natural components of the continental margin, e.g., its plateaus, rises, caps, banks and spurs. Under UNCLOS Article 121(2), an island’s sovereign may claim a continental shelf for the island.