Originally "Silvretta", and built in Slikkerveer, Netherlands in 1948, the 630-tonne vessel was 8.85 metres wide, 3.25 metres deep and 53 metres long. In 1969 Mebo Telecommunications bought "Silvretta", fitted her as a floating radio station, and renamed her "Mebo II." Since "Mebo" was too big to tender "Mebo II" off the Netherlands, RNI used a smaller vessel, "Trip Tender", which Radio London had also used (when she was called "Offshore 1".) The psychedelically-painted "Mebo II" carried a MW transmitter at 105 kilowatts (more than twice the 50 kW TXs used by Radio London and Radio Caroline), though it operated at 60 kW or less.