A 85 ft. yacht
Offshore radio station: "In July of 1960, Radio Cuba Independiente, a broadcast radio station was installed aboard an 85 ft. yacht named Calypso, this was really the first clandestine transmitter operated by exiles in a regular base. The Calypso would stay in the Key Sal Bank and broadcast programs to Cuba from 8 to 10 PM every night on the 49 meters band. The programs were recorded in Miami, sent to Bimini and picked up there. We traveled from Key Sal Bank to Bimini back and forth. That lasted until February 1961, when Radio Swan took control. After the Bay of Pigs invasion, the Calypso was stolen with all radio equipment inside."
Manuel A. Alvarez, a veteran of the 2506 Brigade that invaded Cuba in April 17, 1961 was in charge of the Brigade's communications, related his participation in the first anti-Castro clandestine radio station. Manuel A. Alvarez. 1998. "Radio Cuba Independiente." [Source]
Location: International waters in the Key Sal Bank