USS Amethyst (PYc-3), formerly named Samona II, was a yacht in the United States Navy and served as a patrol boat during World War II. Amethyst was built in 1931 by Craig Shipbuilding Company, Long Beach, California; purchased by the Navy on 4 November 1940 from the estate of Willitts J. Hole, a prominent financier of Los Angeles, California; converted for naval service by Craig Shipbuilding; and commissioned on 27 February 1941, Lt. H. Reich in command.