The career of Washington Irving Chambers spans a formative period in the development of the United States Navy: he entered the Naval Academy in the doldrum years of obsolete, often rotting ships, and left after he had helped like-minded officers convince Congress and the public of the need to adopt a new naval strategy built around a fleet of technologically advanced battleships. He also laid the groundwork for naval aviation and the important role it would play in the modern navy. This work covers Chambers' early naval career, his work at the new Office of Naval Intelligence, his participation in the Greeley Relief Expedition, and a survey for the projected isthmian canal through Nicaragua, before becoming the key advocate for naval modernization. As such, Chambers worked as a pioneering torpedo designer, supervised construction of the Maine, modernized the New York Navy Yard, and became a member of the first permanent faculty at the Naval War College. During his long career, Chambers designed not only torpedoes, but also several warships, including a prototype Dreadnought-style battleship and a host of small devices that ranged from torpedo guidance systems to the first catapult for launching airplanes from ships. At the close of his career, Chambers purchased the navy's first aircraft and founded its air arm. Working with Glenn Curtiss, Chambers guided a coalition of aviation enthusiasts and pioneers who popularized naval aviation and demonstrated its capabilities. Chambers arranged the first take-off and landing of an airplane from a ship and other demonstrations of naval aviation. Combined with his tireless advocacy for modernization, these contributions secured a place in naval and aviation history for the innovator.