Coast Guard Intelligence draws its heritage roots to Caleb Brewster’s involvement in Maritime Intelligence Collection during the American War for Independence and his assignment as one of the first ten Revenue Cutter Captains.
Coast Guard intelligence has its formal roots in the 1915 assignment of a Chief Intelligence Officer at Coast Guard Headquarters. According to Coast Guard Regulations of the time, the duties of that officer included the securing of information which was essential to the Coast Guard in carrying out its duties; disseminating this information to responsible officers, operating units of the Coast Guard, the Treasury Department and other collaborating agencies; and maintaining adequate files and records of law enforcement activities.
Coast Guard Cryptology did not start in 2001 with the inclusion of the Coast Guard in the Intelligence Community, but draws its lineage back to USCG Unit 387 was established in the 1920s as a small embedded unit of the USCG. It did not become an officially named unit until 1931, when it was named the USCG Unit 387 by Elizebeth Friedman. The United States government established this code-communications unit to intercept ship communications and track down prohibition law breakers because “rum runners” were increasingly using radio and code systems for communication. There was an increasing need for code-breaking and encoding capabilities to counter the rum runners, as they were sophisticated criminals attempting to intercept government communications as well. By 1927, the USCG intercepted hundreds of messages but lacked the resources and personnel needed for codebreaking. Therefore, the U.S. Treasury Department appointed William and Elizebeth Friedman, a couple famous for cryptology, to create new code systems for the USCG operations against the prohibition violators and to decrypt the messages accumulating.
The success of Unit 387 was in part due to the USCG interception and decryption capabilities, and their innovation in using USCG patrol boats with High-Frequency Direction Finding (HFDF) equipment created by William Friedman, and Elizebeth’s code-breaking expertise to locate illicit radio stations and rum runners at sea. The USCG today credits these operations as the first tactical law enforcement use of SIGINT in U.S. history. Elizebeth alone decrypted approximately 12,000 messages between rum runner networks over a three-year time span. The unit decrypted a total of approximately 25,000 messages per year during prohibition. From 1927 and 1928 alone, the USCG unit successfully reduced the flow of illegal smuggling by 60 percent, from 14 million gallons of liquor to 5 million, by breaking these coding systems.
With the onset of the Second World War, the U.S. Navy absorbed the USCG Unit 387 with their main responsibilities included monitoring worldwide clandestine radio intelligence and COMINT collection. Twenty-three Coast Guardsmen with the Rating Specialist “Q”, led by Lieutenant Commander Leonard T. Jones, independently solved the cipher of the German high command’s intelligence service, the Abwehr, primarily from transmissions in Latin America, North Africa, and the Far East. Unit 387 was not just a male workforce but included Elizebeth Friedman and 12 SPARs (the name for the Coast Guard Women’s Reserve during World War II, taken from the Coast Guard Latin motto “Semper Paratus” and its English translation “Always Ready”) Although the unit was unofficially conducting clandestine operations, the Coast Guard was officially assigned to clandestine operations outside of the Western Hemisphere, and within the Western Hemisphere in joint operations with the FBI. Throughout WWII, the unit used HFDF technology to intercept approximately 10,000 enemy communications from 65 German clandestine networks and played a key role in cracking the “Enigma G” Code of the Green Enigma, the Red Enigma, the Berlin-Madrid Machine, and the Hamburg-Bordeaux Stecker codes.
In the Pacific Theater, Coast Guard code breaking skills and overall knowledge of Japanese maru (merchant) ships similarly led to deciphering the codes used by those vessels, and ultimately the codes used by the Japanese military. These phenomenal successes were the result of pre-war and wartime Coast Guard intercepts and deciphering of Japanese maru weather and position reports, and the contributions of experts on merchant ship communications, they where instrumental in aiding the U.S. Navy’s Fleet Radio Unit, Pacific (FRUPac) with its major code breaking gains. Such communications intelligence directly contributed to half of the U.S. submarine sinkings of Japanese ships in the Pacific Theater, William and Elizebeth Friedman, Coast Guard cryptography pioneers.
By LT Sean Kilian, USCG