USS Ranger, later USS Rockport and USS Nantucket (PG-23/IX-18), was a gunboat of the United States Navy. A screw steamer with full-rig auxiliary sail, Ranger was destined for a very long 65-year career, serving first as a U.S. Navy gunboat from 1876 to 1920, and later as a training ship with the United States Merchant Marine Academy from 1920 to 1940. The ship was finally scrapped in 1958, but her engine, which is the only one of its type known to be still in existence, was preserved and is on display at the American Merchant Marine Museum of Kings Point, New York.