Complex sentence: The success of Radio Mercur directly inspired other groups of radio enthusiasts to begin their own ship-based stations, in The Netherlands the stations Radio Veronica and the artificial island based Radio Northsea, and in Sweden Skånes Radio Mercur and Radio Nord close to Stockholm.
Split into simpler sentences: The success of Radio Mercur directly inspired other groups of radio enthusiasts to begin their own ship-based stations. These included the Dutch stations Radio Veronica and the artificial island based Radio Northsea along with the Swedish station Skånes Radio Mercur and Radio Nord close to Stockholm.