Coast Guard, United States, an armed force responsible for law enforcement, marine safety, aid to vessels and aircraft in distress, pollution control, and other duties in coastal waters and navigable rivers. It operates within the Department of Homeland Security. This branch of armed services works to protect the public, the environment, United States economic interests, and national security in maritime regions. The Coast Guard emblem was adopted in 1927. The Coast Guard's readiness to meet any emergency and its many duties are indicated by its motto, Semper Paratus, meaning "Always Ready." "Semper Paratus" is also the Coast Guard's famous marching song. Its operating regions include U.S. coasts, ports, and inland waters, and international waters. In time of national emergency, however, control passes to the Navy.

Since 1790, it has seen enormous growth. From a fleet of merely 10 small sailing vessels, it is now a force of modern ships and aircraft. Its members have a proud history of having fought every major war of the United States. The Coast Guard has about 36,000 officers and enlisted personnel. In addition it is equipped with 8,000 reserve members and a 34,000-member, all-volunteer Coast Guard Auxiliary. It also maintains a civilian work force of more than 5,000. Officers are schooled at the U.S. Coast Guard Academy, New London, Connecticut. A requirement for these applicants is that they must be at least high school graduates; less than 22 years of age. They must be unmarried. They must meet rigid physical standards. It is essential for the applicants to be of good moral character. Cadets are appointed yearly on the basis of a nationwide competition.

The eight weeks of basic training for a recruit begins at "boot camp" at Cape May, New Jersey. The training comprises courses in communications, firefighting, first aid, gunnery, military drill, physical education, and seamanship. These courses are conducted by specially trained petty officers. The course encourages them to specialize in a selected field. The Coast Guard tries to place men and women in positions for which they are identified to be best suited.

The Coast Guard Auxiliary is a nonmilitary voluntary organization of several thousand volunteers who help promote safety and efficiency in the operation of small boats. It checks boats for safety equipment, helps with rescues, and conducts classes on boating safety.

Coast Guard headquarters are in Washington, D.C., where the commandant's office is located. The service is headed by commandant of the Coast Guard—an admiral, and is assisted by a vice commandant, a planning and control staff, and various Coast Guard departments. The United States and its possessions are broken up into nine Coast Guard districts; each district being headed by a district commander.

The “active-duty Coast Guard” consists of officers and enlisted men and women who have opted for the Coast Guard as a full time career. This makes up the core of the service. The group members forming the Coast Guard Reserve may be called to active duty anytime during emergency. Their training resembles that of the regulars and includes port security and other wartime missions.

Women in the Coast Guard can serve in any occupational specialty. Women made their first entry to the Coast Guard in 1942 as a reserve group called the SPARS. The name SPAR is derived from the first letters of the Coast Guard motto, Semper Paratus. At that time the SPARS typically filled administrative jobs to relieve Coast Guard men for sea duty during World War II. At the end of the war in 1945, the SPARS consisted of 10,000 enlisted women and 1,000 officers, all of them being discharged or placed on inactive duty by June 1946. The group was finally dissolved. Shortly before the Korean War this group was reactivated in November 1949. But again in 1974, when women became a part of the Regular Coast Guard, the group was disbanded.