Merchant marine -- History -- 2 Prevention 2 Security measures 2 Shipping -- 2 Terrorism -- 2 Boats and boating -- 1 more ... Certification -- 1 Civil defense 1 Civil defense -- 1 Congresses 1 Defenses 1 Globalization 1 Harbors -- 1 Hijacking of ships -- 1 History 1 International relations 1 Merchant mariners -- 1 National security 1 National security -- 1 Naval art and science -- 1 Navigation -- 1 Officers -- 1 Pirates 1 Politics and government -- 1 Safety measures 1 Security measures -- 1 Study and teaching -- 1 War on Terrorism, 2001-2009 1 Watch duty -- 1 less ...