Portable radio in South Coast " invasion " . Operators in gas - masks . An " invasion " of the South Coast was part of the big combined Navy , Army and Air Force operations on the Hampshire coast . The two opposing factions in the " war " are Essex and Wessex , colonies of the two warring European Powers , Redland and Blueland , situated on " New Hampshire " , an island in the Southern Hemisphere . Wessex , having superior naval strength , attempted landing and where opposed by a comparatively small Essex army . The landing was at Studland Beach , near Swanage , Dorset . Photo shows : gas masked man of the invading forces with the portable radio transmitter and receiver self - contained and carried on the back . 25 August 1936 Original caption from negative *** Local Caption ***