In the 1930s, the airfield was used as a training center for military airmen. In 1937, the U.S. Navy moved to the airbase. ("Although the airport managed to survive . . . the Great Depression, the navy's decision to relocate the Great Lakes aviation program to Glenview likely saved Curtiss Airfield." ) The United States Naval Reserve Aviation Base (NRAB) was the name given to the training unit. On November 1, 1939, the base was notified that the Department of the navy had approved a lease on the airport. When the United States joined World War Two, activity increased at the base. It became a major training base for training pilots water-related flying. This included training for aircraft carrier-based flights.