On 31 March 2004 the defendant’s supply vessel Isla Azteca allided with the first plaintiff’s mobile operating drilling unit, the Totonaca , in the Bay of Campeche, some 45 miles off the Mexican coast. Both the plaintiff and the defendant were Mexican entities, and both vessels were Mexican flagged vessels. The allision occurred beyond Mexican territorial waters but within Mexico’s exclusive economic zone (“EEZ”). Under the UN Convention on the Law of the Sea Mexico did not exercise full sovereignty over its EEZ but rather had certain “sovereign rights” within the zone, including control over the economic exploitation and environmental protection of the sea’s natural resources.