"Semper paratus" is Latin for "always prepared." The phrase is best known for being the motto of the United States Coast Guard, though it is also used by a number of other organizations and groups all over the world.
"Semper Paratus" is also the title of the marching song of the United States Coast Guard. Composed in 1927, the music and lyrics were written by Captain Francis Saltus Van Boskerck who, at the time, was Commander of the Coast Guard's forces in the Bering Sea. A second chorus was added to the song in 1943, and the lyrics of the first line of each chorus were changed in 1969.