Mistress of the Air and Some of those Who Built Her. The mighty Martin Mars, 70-ton Navy flying boat and the biggest ship of her type in the world, forms a background for part of the Experimental crew that built her. Thirty-five men, spaced about six feet apart, stand along her 200-foot wing and 215 other persons are grouped before the ship. Announcement of the Mars? conversion into the world?s largest air cargo carrier was made recently by Glenn L. Martin, President of the Glenn L. Martin Company and pioneer developer of huge flying boats. Glenn L. Martin Company, 1941-45. Courtesy of the Library of Congress.