The steady drone of a Catalina flying boat taking off from the waters of Trinity Bay became a familiar sound off Cairns from late 1942. By 1940 a hard-pressed Britain could no longer supply Australia with frontline patrol aircraft and the government turned to the United States. The first order for a total of 18 PBY-5 Consolidated Catalina flying boats was delivered to the RAAF early in 1941. By the end of the war 168 Catalina aircraft had been delivered to Australia and they equipped four squadrons, various air-sea rescue flights, clandestine operations and communications units, and also an operational training unit.

RAAF Catalina No.11 and 20 Squadron base camp on the Cairns Esplanade, was ready for occupation in February 1943. It comprised rows of three-ply gable-roof huts to house about 350 men. The camp extended along the Esplanade from Kerwin to Minnie Street, where the orderly room, medical, dental, radio and operations rooms were situated. The site is now occupied by beach-front apartments and the courts of the Cairns Tennis Club. Nearby stands a 1976 memorial to the 320 RAAF Catalina crew members who died during World War II.