 Subsequently the Radio Caroline ships "Mi Amigo" and "Ross Revenge" would be the only other vessels used to broadcast two mediumwave channels simultaneously.From June 1971 until the end of August 1974 Radio North Sea International was a regular and reliable broadcaster from international waters, four miles from the coast of the Netherlands.The main MW transmissions continued at about 50 kW on 1367 kHz, shortwave using 10 kW on 6205 kHz and VHF FM on 100 MHz.