An archipelagic state is a designation used for certain island countries that consist of an archipelago. The designation is legally defined by the United Nations Convention on the Law of the Sea. An archipelagic state is a designation used for certain island countries that consist of an archipelago. The designation is legally defined by the United Nations Convention on the Law of the Sea. In various conferences, Fiji, Indonesia, Papua New Guinea, the Bahamas, and the Philippines are the five original sovereign states that obtained approval in the UN Convention on the Law of the Sea signed in Montego Bay, Jamaica on December 10, 1982 and qualified as archipelagic states.