United States Coast Guard (USCG)

The United States Coast Guard is a military service and federal law-enforcement agency with eleven statutory missions spanning search and rescue, ports and waterways security, drug and migrant interdiction, fisheries enforcement, icebreaking, aids to navigation, and marine environmental response. It operates under the Department of Homeland Security in peacetime and can transfer to the Navy in war. Its constabulary authority, unlike a navy’s, lets it board, inspect, and arrest under domestic and international law.