ee WEE x Thi at consists at a payee UNITED STATLS PACIFIC FLEET Headquarters of the Comaander in Chief -1 COPY ee | | From; To: . Commander in Chief, U, S. Pacific Fleet Chief of Naval Operations Subj: Danger Area for Operation CASTLE Ref: (a) 1. ales ER OOLLOE 20 December 1752, LA ‘ AUTIORITY.OER 20 BY: DO. R. GIL Nop —22.~GY Ag CNO Secret ltr Op-356/bje ser 00473P36 of 31 oct1 952 In complying with the request of reference (a) for recormendations on a revised danger area for Operation CASTLE, the following factors are cone sidered pertinent: ; @. Eniwetok Atoll and the territorial waters surrounding it have pre-. viously been designated as a closed area in accordance with United Nations Trusteeship agreements, Similar action if not previously completed should be taken to designate Bikini Atoll and its territorial waters as a closed © areas b. The Eniwetok Danger Area, a 150 by 200 mile rectangle centered on Eniwetok Atoll, was originally established both because of danger from _ radioactive fallout and to provide @ convenient "exclusion area" for operations on Eniwetok, The significance of such an area for safety purposes is not of great importance. During Operation IVY, a general surveillance was kept of all shipping within a 500 mile radius of Eniwetok, and specific searches were made in downwind areas for itinerant shipping out to & dig- © tance of 800 miles, It is anticipated that until the phenomena associated with fallout are more clearly established, it will be necessary to. continue such procedures without reliance ona designated "danger area", c. A danger area of moderate size, however, is of considerable com venience for matters of security. Current instructions relative to security provide for denying entry into danger areas to unauthorized vessels and air- creft,. d. _ DOEARCHIVES . In October 19)6, a small rectangular area (12.8 X 22.5 miles) en- closing Bikini Atoll wes designated as a Danger Aree by HYDROPAC 10593. nis aree was labeled as dangerous to navigation and personnel, and entry was prohibited except to those duly autnorized by proper authority. In April 1947, HYDROPAC 10968 cancelled HYDRIPAC 10593 as being sufficiently promulgated in Hydrographic Office Notice to Mariners Number 5 of 196, This area is still listed as a "Danger Area" on charts currently issued and is noted as a "Restrictedérea" in Sailing Directions for the Pacific Islands, Volume I, 1945 (H.0. Pub. No. 165). -f “a ees > eG: zo ar Wik t Bite rs wet 27 cote et motes ibepegt ig ererel of‘whicd Citei=ee waseee 08T er elstionae Ree ee : eee $I