The United States Coast Guard (USCG) is a military branch of the United States involved in maritime law, mariner assistance, and search and rescue, among other duties of coast guards elsewhere.
One of the seven uniformed services of the United States, and the smallest armed service of the United States, its stated mission is to protect the public, the environment, and the United States economic and security interests in any maritime region in which those interests may be at risk, including international waters and America's coasts, ports, and inland waterways.
Today’s U.S. Coast Guard, with nearly 42,000 men and women on active duty, is a unique force that carries out an array of civil and military responsibilities touching almost every facet of the U.S. maritime environment.
By law, the Coast Guard has 11 missions:
Ports, waterways, and coastal security
Drug interdiction
Aids to navigation
Search and rescue
Living marine resources
Marine safety
Defense readiness
Migrant interdiction
Marine environmental protection
Ice operations
Other law enforcement