The requirement for scanning of 100% of maritime shipping containers in overseas ports prior to loading on a ship bound for the United States was enacted into federal law (with various caveats) by the Implementing Recommendations of the 9/11 Commission Act of 2007.
The US Coast Guard adopted the concept of geographic districts when it absorbed the US Lighthouse Service in 1939. Previously, it had no formal segmentation of its chain of command based on geography. Rather, the chain of command was grouped around function.
The trireme was utilized as a warship in the Mediterranean Sea from the 7th century BC until the fall of the Roman Republic at about the commencement of the Christian era. No other warship design has survived in service for a comparable period. It was truly the dominant battleship of its day.
Marine protected area (MPA) is a fluid term with a range of possible meanings. For the most part, it is an area of the marine environment where human activity is regulated for the purpose of conserving and managing natural and cultural marine resources.