For the purposes of this paper terrorism is equated with 'political piracy,' defined as any illegal act directed against ships, their passengers, cargo or crew, or against seaports with the intent of directly or indirectly influencing a government or group of individuals. The historical review of 'political piracy' encompasses the American Civil War, South American insurgencies, the aftermath of World War I, and other 20th century international law developments. The discussion of the Santa Maria incident focuses on the 1961 takeover of the Portuguese passenger ship by insurgent 'passengers' under the leadership of Enrique Galvao. The review and suggested modifications of international legal responses to 'political piracy' focus on the revision of the piracy articles of the United Nations Convention on the Law of the Sea, a multilateral convention on the prevention of terrorism at sea, bilateral and regional agreements on maritime terrorism, the use of nonspecific conventions to combat terrorism at sea, the creative use of definitions, and reliance on customary international law. 122 footnotes.