The major maritime security programs in use today have two separate, but related bases. On a worldwide scope, maritime secuirty is structured around the International Ship and Port Facility Security (ISPS) Code adopted on 12 December 2002 by the International Maritime Organization (IMO). In the United States, maritime security is structured around the Maritime Transportation Security Act (MTSA), adopted by Congress on 22 November 2002. The ISPS Code and the MTSA are very similar. Indeed, the US Coast Guard considers, for foreign flag vessels, compliance with the ISPS Code to be equivalent to compliance with the MTSA for most purposes. The few differences between the two regimes may become significant at some future date, but, for now they are quiescent.