Reply #46: You should do some research. It takes all of 3 seconds:

[qnr]

http://en.wikipedia.org/wiki/US_Coast_Guard - emphasis mine
The United States Coast Guard (USCG) is a branch of the United States armed forces involved in maritime law enforcement, mariner assistance, search and rescue, and national defense, among other duties of coast guards elsewhere. As 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.

The United States Coast Guard has a broad and important role in homeland security, law enforcement, search and rescue, marine environmental pollution response, and the maintenance of river, intracoastal and offshore aids to navigation (ATON). It also lays claim to being the United States' oldest continuous seagoing service. As of January 2005, The United States Coast Guard has about 39,000 men and women on active duty, 8,100 reservists, 7,000 full time civilian employees and 35,000 auxiliarists.

The Coast Guard's motto is Semper Paratus, meaning "Always Ready". USCG has participated in every U.S. conflict from landing troops on D-Day and on the Pacific Islands in World War II, extensive patrols and shore bombardment during the Vietnam War, to Operation Iraqi Freedom. Maritime interception operations, coastal security patrols, and law enforcement detachments are the major roles in Iraq.

The legal basis for the Coast Guard is 14 U.S.C. § 1 which states: "The Coast Guard as established January 28, 1915, shall be a military service and a branch of the armed forces of the United States at all times." On February 25, 2003, the Coast Guard was placed under the Department of Homeland Security. The Coast Guard reports directly to the Secretary of Homeland Security. However, under 14 U.S.C. § 3 as amended by section 211 of the Coast Guard and Maritime Transportation Act of 2006, upon the declaration of war and when Congress so directs in the declaration, or when the President directs, the Coast Guard operates as a service in the Department of the Navy.