The World's Largest Flying boat which the Glenn L. Martin built for Naval Air Transportation Service (NATS), was launched at conclusion of ceremonies held at the company's Strawberry Point Seaplane Base. Launching day coincided with the graduation exercises for future flight and ground crews of the new transports officers and men beside plane. Photograph, July 21, 1945. Official U.S. Navy photograph, now in the collections of the National Archives.