U.S. Courts already rely on UNCLOS as established customary international law

U.S. courts, too, rely upon the 1982 Convention, not as an applicable governing document itself, but rather as the mirror that reflects customary international law. As early as 1994, U.S. federal appeals courts began citing the Convention as a device that reflected international law of the sea principles even though the Convention itself did not apply to the United States. Less than three weeks after the Convention entered into force in 1994 (for signatory/ratifying nations, but not for the United States) the Ninth Circuit Court of Appeals relied, in part, upon the “continuous and expeditious” clause of the Convention’s innocent passage definition to resolve a dispute regarding mooring laws off the coast of Hawaii.⁴⁰ Two years later the First Circuit cited several of the Convention’s exclusive economic zone principles as applicable insofar as those principles were alluded to in U.S. Presidential Proclamations.⁴¹

In 1999, the First Circuit Court of Appeals referred to the applicability of certain provisions of the 1982 Convention, noting that while “[t]he Convention has been signed by the President, . . . it has not yet been ratified by the Senate. Consequently, we refer to UNCLOS only to the extent that it incorporates customary international law.”⁴² That same year, the Fourth Circuit cited provisions of the 1982 Convention regarding salvage law and high seas freedoms as binding, not as treaty law but as well-established customary law.⁴³