Qperation Plan CTG 7.3 No. 1-53 (3) Overt Action by Vesselor Aircraft. (4) Raids. Overt action by vessel or aircraft could take the form ofattack by bomb, guided missile, gunfire or assault, Raids could be conducted by aggressive or surreptitious methods underthecover of darkness from ships and submarines, or possibly, from aircraft. The landing and recovery of raiders by submarine could be accomplished under the conditions of darkneas and the confusion resulting from their activities. (5) Photography and Observation. Compromise could be accomplished by photographic means from surface ship, aircraft or submarine. Unobserved submarine approach within one mile of important islands of the atoll or overflight by unfriendly aircraft are possible. In addition, a determined surfact ship commander might attempt to compromise the operations by overt observation of activities in the area from immediately outside the three (3) mile limit. By such means, periodic photography and observation could record and interpret the progress, process of preparation, types of construction and the approximate time of important opcrations from the activities within the atoll, (6) Unauthorized Instrumentation. Means under this heading for obtaining unauthorized information would include pressure, heat and radiation detection devices as well as radioactive material collection devices. (7) Declaration or Commencement of War. In the event of the commencement of war, by declaration or otherwise, involving the United States, the nature and extent of CASTLE Operations might be radically changed. It is difficult to predict the exact nature of these changes, but if the Operation were continued, partially, wholly or augnented in scope, a complete re-evaluation of enemy capabilities and intentions would be necessary. b. USSR Naval Capabilities. (1) Submarine Capabilitics. If he decided to utilize his submarine capability to obtain information concerning, or to interfere with, CASTIE Operations, the Soviet might employ submarines as follows: DNA (A) To instrument the shots by the erployment of pressure, heat and radiation measuring instruments located on board. The submarine probably would have to come to the surface to employ thcse instruments, although it is not impossible to mount them on periscopic extensions from a submerged submarine in which case the detection of the submarine would )27