The U.S. Navy's answer to the Radioactive Waterburst
A curious addition to many early civil defense films was the anticipated threat of a "radioactive waterburst". Essentially an underwater nuclear detonation, the belief was that, if unleashed in the harbor of a large coastal city, the waterburst would send millions of gallons of radioactive water into the air which would return to the ground in the form of fallout laced rain. Cities and surrounding suburbs would then be inundated with the deadly meteorological situation, and vital ports and harbors would be rendered useless as blast forces and radioactivity shut them down. The fear of such an event appears to stem from the underwater testing of bombs during Operation Crossroads. In July of 1946, the U.S. Navy and other branches of the armed forces tested two atomic weapons at the Bikini Atoll. The first shot, Able, was detonated at a high altitude, creating limited damage. The second bomb, Baker, was detonated just under the ocean's surface, effectively destroying many of the scrapped warships placed around the epicenter, and producing startling amounts of radioactivity which were not detected in the airburst. Until further atomic testing revealed in 1954 that radioactivity traveling through air was just as harmful as that which fell through water, films often depicted radioactive rain as the sole lingering threat of an atomic attack.
Stressing the use of naval dry dock facilities which can be easily quarantined to handle contaminated ships, the film explains how the decontamination squads will don protective over clothes and radiation survey equipment in a change station which will double as a headquarters for civil defense operations in the area. Traveling to stricken vessels via a special tugboat adorned with striped buoys, the squads will monitor radiation level on board ships in the quarantined area and prescribe specific levels of decontamination. Personal dosimeters and monitoring strips are to be used to keep the servicemen from receiving fatal douses of radiation. Despite these precautions, the men in the decontamination squads are further instructed, once their inspection is complete, to remove all clothing and thoroughly scrub themselves in the change station while searching for any open wounds which could allow radiation to enter the body. Interestingly, while this process is painstakingly described in the film, Industrial Radiological Decontamination of Ships never indicates whether these operations would be conducted exclusively on naval ships, or private commercial ships as well. The word Industrial in the title suggests that commercial ships would be subjected to this process following a waterburst, however, the film was designed specifically for the navy and is set within an unnamed naval shipyard. This vague sense of who would be entitled to such extensive attention and resources following an attack fits well with the atmosphere of civil defense in the early 1950's, where many ideas and procedures were conjectured, and some even put to film, but the details behind their execution remained frustratingly hazy.