Sigsbee, Charles Dwight, 1845–1923, American naval officer, b. Albany, N.Y. He saw service in the Gulf of Mexico in the Civil War, was subsequently stationed with the Asian squadron, taught at Annapolis, and served (1873–88) in the Hydrographic Office and the Coast Survey. There Sigsbee invented several marine instruments that revolutionized deep-sea exploration. He also made the first complete deepwater survey of the Gulf of Mexico. In 1897 he achieved the rank of captain and commanded the Maine until it was destroyed in Havana harbor. He was commended for his conduct pending investigation of the incident. While in command of the St. Paul in the Spanish-American War, Sigsbee defeated the destroyer Terror and the cruiser Isabella II. Commissioned as rear admiral (1903), he commanded the Caribbean squadron and then a squadron of the Atlantic Fleet. He wrote Deep-Sea Sounding and Dredging (1880) and The "Maine": an Account of Her Destruction in Havana Harbor (1899).