"Invisus videns" ("Seeing through the unseen")
History of 684 Squadron:
No.684 Squadron was formed at Dum Dum from a nucleus supplied by No.681 Squadron on 29 September 1943 for photographic reconnaissance duties in South-East Asia. While No.681 operated Spitfires, No.684 provided longer-ranged aircraft for missions over Burma, Siam and Malaya. The Mosquito was the main type used but Mitchells were flown until May 1945. A detachment was based in Ceylon in September 1944, which covered the Dutch East Indies until the end of the war, and in October 1945 the squadron moved to Saigon. In January 1946 it was transferred to Siam where it carried out survey flights, until renumbered No.81 Squadron on 1 September 1946.